A memorial marks the spot of the fatal crash in Montgomery County. (Donna St. George /The Washington Post)

Just before midnight Thursday, the 2006 Acura TSX approached a bend along Dufief Mill Road in North Potomac. Its young driver and three passengers had been at a party where there had been underage drinking, according to police. They were going fast — very fast — in a 30-mph zone, police said.

In one fleeting moment, the 18-year-old driver lost control of the vehicle. It veered into a driveway, vaulting into the air and thudding into a tree. It struck another tree and a fence and overturned by the time it came to rest in a homeowner’s side driveway, according to authorities.

Four weeks after graduation, Wootton High School’s Class of 2015 lost two of its own: Alexander Murk, 18, of Potomac, and Calvin Jia-Xing Li, 18, of Rockville. A third graduate, Samuel Joseph Ellis, the driver of the car and the school’s star quarterback, was hospitalized in critical condition, and a fourth teenager, a 17-year-old Wootton student, suffered minor injuries, police said.

A few cans of beer, still cool to the touch, were found in the car’s wreckage, according to police. Police believe speed and alcohol contributed to the crash.

The tragedy came as a heart-rending marker of a season when many parents fear that the exhilaration of the end of high school and the start of summer — with its parties and proms and beach outings — will lead teenagers toward risky actions with anguishing consequences.

“Good kids make bad decisions, and when they are involving alcohol, they oftentimes deal with tragedy,” said Capt. Tom Didone of the Montgomery County police, adding that the circumstances brought to mind the “River Road” crash of 1994, in Bethesda, which killed two teenagers and left two others seriously injured.

The crash is emblematic of what AAA considers a disturbing and persistent phenomenon: Teen drivers, especially when they are out of school for the summer, are involved in frequent fatal crashes. The driver advocacy organization released a report last month calling the period between Memorial Day and Labor Day the “100 Deadliest Days,” a reference to the fact that teen fatalities typically climb during that period.

“It is a haunting pattern,” said John B. Townsend II, AAA Mid-Atlantic’s manager of public and government affairs. “We pass all these tough laws, and then another generation comes along and makes the same mistakes we’ve seen in the past.”

The late-night crash has left the Wootton community devastated, Potomac resident Monica London said Friday as she placed flowers near a memorial made of two tree branches fashioned into a cross and adorned with a small American flag. On Twitter, students wrote Friday that they planned to gather at the school’s football field in the young men’s honor

“They were all really good kids, great athletes,” said London, whose son, a rising senior, played football with two of the students. “And they all had really promising futures. They were all headed to college.”

Two teenagers were killed and one was left in critical condition after their car crashed in Montgomery County late Thursday following an underage drinking party. (WUSA9)

A preliminary investigation showed the two passengers in the back seat were not wearing their seat belts. They were pronounced dead at the scene, police said.

When police arrived at the home where the party had taken place, teenagers were outside, and it appeared that the party had ended, Didone said. A parent answered the door when an officer knocked, he said. Several teenagers were cited for underage alcohol possession.

As some visited the roadside memorial, others took to social media, tweeting with hashtags including #RIPAlexandCalvin and #woottonstrong.

“Sometimes the greater plan is kinda hard to understand . . . cant believe you’re really gone,” one tweet read.

Michael Doran, the high school’s principal, said in an e-mail to The Washington Post that he had visited the hospital and called the parents of the two students who died.

“All I know is the outpouring of support that the Wootton community is surrounding the families with is heartwarming,” he wrote.

Some of the students were well-known athletes. Ellis, of North Potomac, had been accepted to the University of South Carolina and broke the state record in 2013 with 557 passing yards in a game against Rockville High School. Li played wide receiver for the Wootton team, and Murk played for the school his freshman year.

The families of the teenagers declined to talk in detail about the young men.

“It’s too painful,” said a woman who identified herself as Murk’s grandmother. Efforts to reach family members of the other young men police identified were unsuccessful.

According to a AAA analysis of government data, an average of 220 teen drivers and passengers died in traffic crashes during each of the summer months, a 43 percent increase from the rest of the year. Townsend said that is because teens, especially those who have recently graduated, are out of the school during the summer and face less supervision.

“That age group, from 16 to 20, still has the highest number of traffic fatalities in the country,” Townsend said. “When you combine speed, alcohol and youth, it’s a recipe for disaster.”

Eddie Tolliver, Wootton’s football coach, said he was “very surprised” to hear about the incident.

“No one ever expects anything like this to happen,” he said.

Irene Brodsky, a football team mom, called the incident “really tragic.” She declined to comment further or provide any information about the people involved. “We’re just keeping the families in prayer,” Brodsky said.

On social media, others grieved more openly.

“Can’t stop crying,” one tweet said. “God please take Calvin and Alex with open arms to the heavens and please take the pain away from all the loved ones.”

Elizabeth Koh, Jennifer Jenkins and Dana Hedgpeth contributed to this report.