Five years ago, the lives of MIT officer Sean Collier’s sister, MBTA officer Dic Donohue and former Watertown Police Chief Ed Deveau changed forever.

Appearing on Greater Boston with host Jim Braude, they reflected on the days following the bombings at Boston Marathon finish line, the unity that’s endured because of those events, and Collier's life and legacy.

“I have the very public story and the very public image of Sean that people know and have heard about, and then I have, you know, my little brother and all the memories of growing up with him,” Jennifer Lemmerman, Collier’s sister said.

In 2013, just days after detonating two bombs on Boylston Street, Dzokhar and Tamerlan Tsarnaev shot and killed 27-year-old Collier while he was sitting in his patrol car. The brothers then got into a shootout in Watertown, where Donohue was injured by friendly fire and nearly bled to death.

Donohue said he has fond memories of Collier, whom he called “a really good friend” and dedicated public servant. “We had lots of conversations on the way in and out of the academy and formed a great friendship, not only as police brothers but as friends,” he said.

Since his death, a memorial fund has been set up in Collier’s name. This Wednesday, an event — “Stronger After 5” — will honor the marathon bombing victims, including Martin Richard, Krystle Campbell, Lingzi Lu, as well as the many survivors. Proceeds raised at the event will go to the Sean Collier Memorial Fund, which Lemmerman said aims to support law enforcement and programs for underserved youth.

Deveau said it has been “remarkable” to see how the city has rallied behind the survivors and their families and how they’ve given back to Boston.

“These peoples … lives could have went a different way. And now the resiliency — and it’s all supported by all the people in greater Boston, and its just remarkable, Jim, what I see day in and day out.”

For more information about " Stronger After 5," click here.

This post has been updated