Her play, "Utility Monster," won best stage reading in a playwriting festival in Manhattan, according to her mother. In it, she struggled with values and life's meaning: "How can I justify eating at Taco Bell if it can save a child in Africa? Is it indulgent for me to buy art?"
"The only solace for what happened [to Keegan] is she was able to leave a written legacy so vivid," said De La Bruyere.
Keegan wrote a full-length musical, called "Independents," with lyrics by close friend and classmate Mark Sonnenblick, which is slated to go up at the New York Fringe Festival in August.
The story, about 20-something slackers living and working together on a Revolutionary War re-enactment ship and running drugs, is a comedic look at the transition to adulthood.
"She was always writing about things she thought about, wondering is there a network of friends who can sustain you or ultimately hold you back from being an adult," said Sonnenblick, who is from Manhattan Beach, Calif.
He and other collaborators spent the last week on Cape Cod, supporting the Keegans and revising the play.
"Her voice is there on the page and in our head," he said. "It's a fact she won't be around to see it or participate in the process, something that just hasn't sunk in."
Friends like Amalia Skilton said Keegan could "be wild" like other college kids, but she also had a sense of fairness and little ego.
Skilton worked with Keegan in the Democratic primary elections for city council in New Haven, Conn. When it looked as if their candidate would run unopposed, Skilton was elated, but Keegan didn't see it the same way.
"She really cared about having a conversation and people thinking critically about what they were doing," said Skilton, a senior from Phoenix. "That hurt her candidate, but it's what set her apart from so many at Yale. She did it not to glorify herself."
The Keegans, who have raised their children in suburban Wayland, Mass., were good role models for their daughter and her two brothers, Pierce, a junior at Wayland High School, and Trevor, 25, who runs a small business.
They describe themselves as "humanists."
Tracy Keegan had worked in film production, but turned her efforts to raising three children and charity work.
Kevin Keegan spent 25 years as an executive in software sales, then became an eighth-grade social studies teacher, a career change his daughter was proud of. When the economy turned, he was laid off and has returned to sales.
As a child, Marina was diagnosed with celiac disease. She later became the poster child for an educational DVD her mother created on behalf of children afflicted with chronic illness. "It was rough," said Tracy Keegan,
Despite health obstacles, Marina went on to politics in high school, and was one of the youngest interns in the 2008 campaign to elect Barack Obama. In college, she traveled to India on a Cyrus Vance International Scholarship.
The "seeds" of her passion came from her family, who emphasized "the right thing to do, to help your community," said Kevin Keegan.
For the Keegans, the right thing to do was to help Gocksch, who was "devastated" by Keegan's death and his role in the accident.
When Gocksh came to see the Keegans several days ago, they gave him a hug. "We said this horrible accident was her fate," said Tracy Keegan. "Unfortunately, she could not throw two lives away, and she loved you."
"You can't go off course," Kevin Keegan told him. "To honor her, you need to live your life -- to make a difference for others, to embrace life as she did."
The Keegans believe their daughter was "wise beyond her years" and made a mark on a campus that won't forget her.
"She inspired young people to make a difference and to realize that they can roll up their sleeves and do something," said Tracy Keegan. "This is their world, their future."
Still, they are numb by the loss. "We loved her," said Kevin Keegan. "As a father, I selfishly wanted more time with her."
On Class Day before graduation, the speaker, ABC's Barbara Walters, asked Keegan's class how many students had "found your bliss in life?" Only a few raised their hands.
"The point was that not everyone had a clue about true inspiration," said Tracy Keegan. After the speech, her daughter confessed to her mother, "I was one of the people who raised their hands."
Kevin Keegan's last memory of his daughter is graduation weekend at Yale. As his wife stayed on to pack up, he said goodbye on a street corner.
"I told her I was so proud of her and loved her and I had a tear in my eye," he said. "I told her how much it all meant to me and got in the car, like I always do and started beeping the horn and yelling. She was smiling."