Danalee Ariel Casey doesn’t remember walking to the bus stop that morning, or stepping onto a busy rain-slicked street, or feeling a Mercury Marquis slam into her body, leaving her moaning on the ground as a stranger held her hand.

Neither does she remember the weeks that followed. How doctors removed two large pieces of her skull. How her head swelled so much that her ears folded inward. How her husband stayed by her bedside, not knowing if she’d wake up, and, if she did, whether she’d be the same person he’d known since he was a teenager.

“I was fully prepared to change diapers for the next 60 years or so,” Mike Casey, 32, said one recent morning, watching his wife take slow but unaided steps at a Rockville outpatient rehabilitation center.

Any pedestrian who has jumped back to avoid a careering car, or any driver who has stopped short of a jaywalker knows this about Washington’s busy streets: People and vehicles all too often collide. Sometimes, as was the case with an 8-year-old Alexandria boy this week, such a collision ends in death. But more often, it results in serious injuries that can require months, sometimes years, of painful, uncertain recovery.

Nationally, there is a pedestrian fatality every two hours and an injury every nine minutes, according to the National Highway Traffic Safety Administration. In 2009, more than 4,000 pedestrians were killed and an additional 59,000 injured.

In many ways, Danalee Casey’s case is unremarkable. She was struck by a car on a rainy October morning blocks from her Silver Spring home. But doctors, relatives and the man who hit her — and who, unlike Casey, remembers every detail of that morning — describe her recovery as nothing short of extraordinary.

Just as he did every day, on Oct. 13, Alex Barnatny of Kensington drove west on Veirs Mill Road on his way to work as a driver for Enterprise Fleet Management. It was after 7 a.m. when he cruised past the crosswalk, he says.

Then he saw her.

“One second the road was clear, and the next she was in front of me,” he says. “And I couldn’t avoid hitting her.”

The windshield shattered from the impact, and when Barnatny stepped out of the car, he found the redhead on the road, blood pooling around her. He wouldn’t know until later that it was the day before her 31st birthday. He called for an ambulance.

“I held her hand,” he says. “I was so scared she was going to die right there.”

In the hours that followed, doctors worked on Casey at Suburban Hospital, and Barnatny, 61, went to church to pray.

“Everybody I know prayed for her,” says Barnatny, who was not charged. “I think they’re still praying for her.”

The accident left Casey with a broken leg and bleeding on her brain. Doctors at Suburban removed two pieces of her skull and implanted them near her stomach, where they would remain until the swelling subsided.

Once he knew she would probably survive, Mike Casey decided it was best to deliver the reality straight to their 11-year-old son, Mike Jr., who has learning disabilities: “I told him, ‘It looks like Mom is going to live, but we don’t know if she’s going to wake up. And if she wakes up, we don’t know if she’s going to come back.’ ”

The couple met at Hyattsville Middle School. He was in eighth grade and she in seventh when they ended up in drama class together. As both tell it, she knew she would marry him when he correctly pronounced a word others in the class didn’t know: countenance.

For their entire relationship, Mike Casey says, his wife has been the optimist, the one who believes everything will work out. He has been the pessimist, who believes, despite her assurance, that it won’t. Together, they both kicked drug habits and raised a son who was born 31 / 2 months premature, no wider around than his mother’s wrist.

Before the accident, they were looking to buy their first house, and Danalee Casey was anticipating a promotion in the Dupont Circle office where she works as a legal secretary.

“I don’t believe everybody is a beautiful and unique snowflake,” says Mike Casey, a home-improvement worker. “Most people aren’t special.” But of his wife, he says, “There is just something different about that girl.”

By their unofficial count, about 4,000 people prayed for them across the country — relatives in Arkansas, friends in Maryland, strangers in states they’d never visited. A Web site set up to track Casey’s progress received more than 12,000 visits.

“I tried to explain it to the nurses at Suburban and [the National Rehabilitation Hospital] because everybody was saying, ‘Oh, my gosh — you’re here all the time. You’re a great husband,’ ” Mike Casey says. “I’m not really a great guy. The fact that I’m here right now is not about who I am. It’s about who she is. They didn’t know her yet.”

Casey spent 21 / 2 weeks in a coma before being transferred to NRH in the District. There, Kritis Dasgupta, a doctor who specializes in rehabilitating those with brain injuries, worked with her along with a team of therapists. The first time he saw her, Dasgupta says, Casey’s right arm remained limp against her body and she struggled to follow simple commands, such as to raise her hand or stick out her tongue.

“When you have a significant traumatic brain injury, as she had, the first thing to worry about is survival,” Dasgupta says. “But often the bigger question is: Will she be herself again?”

A large metal brace now juts from Casey’s leg. Her once shoulder-length hair is cropped into a short Mohawk framed by two large scars. Her right eye looks off in the wrong direction, causing her to see double. But mentally, by all accounts, she is healing well. As she describes it, once doctors replaced the pieces of her skull, it felt as if her brain “rebooted.” Her memories came back chronologically but stopped short of the morning of the accident.

By the time she was discharged on Christmas Eve, to the surprise of her son (whose reaction was captured on video), she had use of her right side again and was working on Excel spreadsheets.

“I started reading Kurt Vonnegut when I was very young, and I think that helped me a lot because that’s where I learned: So it goes, stuff happens, get over it,” Casey says.

A few weeks after she returned home, Casey called Barnatny. She knew he’d been tracking her progress on the Web site and had, at one point, sent his priest to the hospital. She wanted to let him know that she was okay, that she wasn’t angry.

Barnatny was sitting in his car outside his job when the phone rang. It was just a few days before Russian Orthodox Christmas, which he celebrates.

“It was kind of a Christmas present for me,” Barnatny says. “I told her that I really thought it was a miracle that she got so much better in such a short time.”

In some ways, Barnatny says, he, too, is healing. Pedestrians now make him nervous when he drives.

“I think of that day a lot,” he says. While Casey doesn’t remember the accident, “I don’t think I’ll ever forget it.”

Casey and her husband both find it hard to believe that she wasn’t in the crosswalk at the time of the incident, because she was usually so diligent about that. But at this point, she says, it doesn’t matter.

“Accidents happen,” Casey says. “I’ve always, since I was a little person, thought there is 85 percent of my reality that is really under my control. And then there is 15 percent, like the weather, or the Metro or the fact that I got hit by a car, that I can’t do anything about. And I could respond negatively and be miserable. Or I can try and see what I can [learn from] it.”