The country woke up with Triple Sec and cranberry juice on its breath. Just out of reach: the scuffed brick of a Nokia phone, a bottle of pills to stoke the serotonin, 2½ pounds of more than you needed to know about President John Adams. The phone on the nightstand couldn’t read the news, so on went the television. Something about a woman in the Houston suburbs who drowned her five children in the bathtub. And that D.C. intern — another intern scandal — was still missing, and her parents were suspicious of a congressman with whom she allegedly had an affair. In Las Vegas that week, Whitney Houston accepted a BET lifetime achievement award at the ripe old age of 37.

“I’m a survivor!” she exclaimed, echoing a Destiny’s Child hook from the spring, and made a prediction: “The best is yet to come.”

It was the first day of the summer of 2001, leery and languid. The new president, George W. Bush, had recently signed a $1.35-trillion tax cut, but the economy was stalling. The tech bubble had burst, but Americans were still lounging on the bloat of prosperity. Kenneth Lay, a pal of Bush’s, had been crowing about the health of his energy-trading company, Enron, which was reporting $50 billion in revenue. Engineers in Silicon Valley were readying a top-secret gizmo, code-named “P-68.”

Pax Americana was only just yielding a hangover. We were still buzzed and loose, with only twitches of a dawning headache. The country felt cuspy, for better or worse.

John Milton Wesley felt ascendant. He had gotten out of debt. He was working out and going to church and writing regularly. As deputy director of communications for the Baltimore City Housing Authority, Wesley was preparing some of the city’s developments to serve as the backdrop for an HBO series titled “The Wire,” which would begin shooting that fall. He was 52, but he felt like he was just starting his life.

That feeling had a lot to do with Sarah Clark, a middle school teacher. They were engaged. Wesley had been a bachelor for decades but now, for the first time in his life, everything he needed was in one place, with Sarah. As summer arrived he felt the warmth of possibility.

Possibility. That’s what Feisal Abdul Rauf saw in Lower Manhattan, where he presided over Friday prayers at his mosque. The 52-year-old imam had tried and failed, the previous year, to raise money for the Islamic equivalent of a Jewish Community Center or the 92nd Street Y — something that could help build bonds between Muslim immigrants and their new American neighbors. It would have to wait. Imam Feisal turned his focus to the coming wedding of one of his twin daughters, the first of his four children to marry. He reminded himself that if something is meant to be, God will make it happen — once “everything is right.”

Amy Ting, a 23-year-old actor, was doing publicity for her first movie, “Miss Wonton,” which had premiered at the Sundance Film Festival with the tagline “Life is a menu of choices.” She loved the entertainment industry, and was still submitting audition tapes, but decided not to put all her eggs in one basket. This was the summer she would interview for a management position at the Marriott where she worked at the southern tip of Manhattan.

Her rail commute from Elizabeth, N.J., began at 3 a.m. Her shift started at 5. After work she would walk the bridge over the West Side Highway to Starbucks for a caramel frappuccino with whipped cream. Evenings were for Broadway shows and dancing in smoky Manhattan lounges to Janet Jackson and Aaliyah, the 22-year-old pop singer who released a self-titled album that July. Ting earned extra cash by performing with a Hawaiian luau troupe at cultural festivals in the tri-state area. Sometimes, rather than go all the way home to Jersey, she slept on a bench in the employee work room at the Marriott, hugged between the two towers of the World Trade Center, her dress suit and silk scarf ready to go at dawn. Summer ’01: glamour and hustle.

This is my prime, she thought.

Women wore hoop earrings and tight white tank tops. Men’s hair spiked in the front. Sarah Michelle Gellar, vampire slayer, was on the cover of Seventeen in a choker and snakeskin-patterned pants. Mariah Carey was exhausted. Carrie Bradshaw was upstate with Aidan, stilettos catching in mud. The average 20-something was forestalling marriage and job-hopping every 1.1 years.

“What I’m seeing in my clinical practice is that all the stages of life are now being telescoped,” a psychologist told the New York Times that June. Midlife crises were hitting at the quarter-life mark.

More than a thousand feet above Amy Ting’s Marriott, in the World Trade Center’s North Tower, a 37-year-old artist named Monika Bravo set up a studio for the summer. She had won a fellowship from the Lower Manhattan Cultural Council to work in a corner of raw office space with other artists, and hoped to film clouds moving through the skyline — which reminded her of the mountainous vistas in her native Colombia.

Gratitude wrapped in naivete. That’s what Bravo felt with the breeze in her face as she biked across the Brooklyn Bridge to her temporary studio. America didn’t seem real. She was on top of the world in her adopted country, viewing it from a perch that was worth $3.2 billion — the cost of the lease signed July 21, 2001, by New York businessman Larry Silverstein. But the space on the 92nd floor of the North tower was a dump: a layer of dust, bare bulbs and broken office chairs. The tower’s 22-inch-wide vertical windows felt more like a prison than a portal. Bravo covered the panes, voiding the view, and concentrated on making an interactive installation that would include prints inspired by the poetry of Jorge Louis Borges.

To gaze at the river made of time and water

And recall that time itself is another river …

Her Sony DV camera was always nearby. Through June, July and August she waited for good clouds to roll in.

It was a wet, hot American summer; “Wet Hot American Summer” premiered. “American Pie” came back for seconds. “Jurassic Park” completed its trilogy, with the Spinosaurus replacing the T. rex as the most fearsome dino-villain. (“It’s very subtly different in a fundamental way,” director Joe Johnston, who subbed for Spielberg, said of his installment.)

Shortly after the Fourth of July, an 8-year-old Mississippi boy was mangled by a bull shark on a beach in Pensacola, Fla. In the following weeks, the media swarmed every glimpse of a dorsal fin. “The summer of the shark,” concluded Time magazine, stamping the words in big yellow text on its cover, though there was no actual spike in shark attacks.

All summer the word “spectacular” was used in intelligence reports to describe al-Qaeda’s plans for terrorism in the United States.

Agents were combing through the D.C. intern’s browser history for breadcrumbs. There were no good clues or answers; Americans entertained themselves by speculating about what might be below the surface.

Below the surface, the Houston mother who drowned her babies had been suffering from postpartum psychosis. Senior managers at Enron were slipping out the exit. Whitney Houston’s life was falling apart.

After her eighth-grade graduation, Alexandra Wald’s stockbroker father, Victor, had brought her to a Barnes and Noble, paid for a stack of books that included “The War of the Worlds,” “1984” and “Crime and Punishment,” handed them to his daughter and said, “Here, enjoy your summer.”

Alex, 13, wanted to know everything her hyper-intellectual father knew. She tore through the reading list and rarely missed their standing date to watch “The Sopranos” on Sunday nights at their apartment on the Upper West Side. Alex thought Eminem’s lyrics were genius, but Victor objected to the rapper’s language and attitude toward women. So, she had a friend record “The Marshall Mathers LP” onto a cassette tape, then she labeled it with another artist’s name and popped it into her Walkman.

The thrill and anxiety of entering high school in the fall had occupied her mind since the spring.

“I’m sort of looking forward to it, but I’m really scared,” she’d written in her diary back in May. “I hope I’ll look back at this and laugh.”

Her biggest crush was one of the few kids she knew who’d be going to her new school. She was desperate to lose the last of her baby fat, to find the perfect first-day outfit, perhaps among the racks of Abercrombie & Fitch or Pacific Sunwear. She eventually settled on a fitted, lavender Beatles shirt she found in SoHo, hoping it would not come off like she was trying too hard. Over lunch with her dad, just before the start of the school, Alex confessed her brewing social anxieties.

“Boys are going to line up around the block for you one day,” said Victor Wald, who was just starting a new job on the 84th floor of the North tower of the World Trade Center. “You’ll see.”

In Cupertino, Calif., Apple’s secret “P-68” project, soon to be known as the iPod, was on track for a fall release. Engineers got a prototype of the device to play its first song: “Groovejet (If This Ain’t Love).”

One night that summer, John Milton Wesley dreamed that he was accompanying Sarah Clark on a shopping trip, and she never emerged from the fitting room. An attendant told him she had disappeared and was not coming back.

“What do you mean she’s not coming back?” he screamed. He woke up crying, acutely aware of how much he loved her.

“I’m right here,” Clark told him. “Go back to sleep.”

In August, the couple embarked on a 10-day road trip from Maryland to Nova Scotia. As they drove, Wesley, who had gone to college on a vocal scholarship, sang along to a mix tape Clark had made. “Heavenly Father, watchin’ us fall …” he crooned in time with James Ingram and Michael McDonald. Their excitement about the journey was tinged with sadness: Two friends of theirs had died suddenly, right in a row. The couple had planned to marry the following April, but as they drove Clark asked, “What would you think about us moving the wedding up?” They decided to marry that December.

On Aug. 30, as part of messy divorce proceedings, outgoing New York mayor Rudy Giuliani was depositioned for seven hours at the office of his wife’s attorney.

On Aug. 31, the body of Aaliyah, who had been killed in a plane crash in the Bahamas, was carried in a glass hearse on a horse-drawn carriage through the Upper East Side.

Richard Clarke, Bush’s chief counterterrorism adviser, wrote to Condoleezza Rice, the national security adviser, on Sept. 4: “Are we serious about dealing with the al Qida threat?”

The reality competition show “The Amazing Race” premiered on Sept. 5, and scientists involved with NASA’s two-year-old Chandra X-Ray Observatory announced that they were pretty sure they were staring into a black hole — “looking down into its gaping maw, if you will,” said one astronomer, “and seeing what is happening around the event horizon.’’

On Sept. 6, Florida wildlife officials banned diving-trip operators from using chunks of fish to attract sharks so tourists could play with them.

Wesley’s fiancee, Sarah, was due to accompany a student on a field trip to study ecology in California the following Tuesday — the same day Wesley had the first day of filming for “The Wire.” Her flight was out of Dulles. That Sunday, Sept. 9, the couple visited a wedding venue in Baltimore’s Cherry Hill neighborhood. It had a veranda overlooking the water. It was perfect.

On Sept. 10, Imam Feisel officiated his daughter’s nuptials in the mountains of Colorado. Back in Manhattan, Victor Wald escorted Alex to her high school orientation; though it was embarrassing, she let him give her a kiss. That afternoon Monika Bravo aimed her camera out the window of the 92nd floor as a storm finally rolled in. Rain drizzled down the narrow panes. By nighttime, lightning was striking New Jersey. Some floors of the neighboring South Tower were illuminated, and some were dark. Bravo considered staying overnight to do a 24-hour time lapse video of the roiling vista, but she was out of cigarettes and did not have any food. At the urging of her husband, she decided to go home to Brooklyn Heights. She could have left the tape of the storm — she would be back tomorrow, after all — but decided to slip it in her bag.

Monika Bravo's video of Sept. 10, 2001

In Elizabeth, N.J., Amy Ting prayed to Buddha for good luck; she had her interview the next morning for a manager position at World Trade Center Marriott at 9 a.m. She arrived before dawn on Sept. 11 in her company suit and scarf.

The previous night’s storm was gone, leaving Manhattan in the clear blue. Alex Wald’s father Victor was still in bed when she was getting ready for her first day of high school. He would eventually head downtown for work on the 84th floor of the North tower, eight floors down from Monika Bravo’s studio corner. Alex pulled on her lavender Beatles shirt and walked 10 blocks to start her next chapter. The summer was not technically over, but it was ending, slowly and then all at once.

Epilogue: Amy Ting crawled out of the rubble of the Marriott and spent four years in the Air Force as a physical therapist assistant and volunteer with the honor guard at Dover Air Force Base, where she carried the caskets of fallen servicemembers; now Amy Andrews, she works with children with special needs in Maryland. Imam Feisel founded a nonprofit called Cordoba House to increase cross-cultural understanding; the Muslim community center he proposed, which became known as “the Ground Zero mosque,” was never constructed. John Milton Wesley still performs songs he wrote in tribute to Sarah, whose plane was crashed into the Pentagon. Monika Bravo called her video of the Sept. 10 storm “Uno nunca muere la víspera,” which translates roughly to “You never die the day before you’re supposed to die”; she moved to Miami Beach last year and is now working on a public-art commission for the city of Boston that uses glass mobiles to evoke words such as “courage” and “communion.” Alexandra Wald now goes by her married name, Bortz, and works in cybersecurity at the Department of Homeland Security, trying to prevent the kind of terrorism that killed her father.

Correction: An earlier version of this story referred to New York’s 92nd Street Y as the 92nd Street YMCA. The cultural and community center is not affiliated with the YMCA. This article has been corrected.