CAMBRIDGE — Israel Ruiz was in a car driven by Officer Sean A. Collier on a Friday evening in February 2013 during the height of a fierce snowstorm. Collier, who had picked up the MIT official at South Station after a trip to New York, was driving him home down Boston streets, now deserted as snow piled high and winds blew.
Collier stopped his cruiser at a red light. That was when a young man ran up and asked for directions.
“With his kind demeanor, Sean helped this stranger find his way,’’ said Ruiz, MIT’s executive vice president and treasurer. “The light switched to green and back to red — a couple of times.’’
Ruiz said the 26-year-old Collier exhibited that same willingness to help in his final moments, when he was shot by the Boston Marathon bombing suspects while sitting in his cruiser a year ago on Friday, authorities allege.
“Officer Collier had the same instinct to help when asked by strangers,” he said. “Only this time, right there, the worst evil was on the other side of that window.”
Ruiz joined US Senators Elizabeth Warren and Edward Markey, other MIT representatives, and Mayor David Maher of Cambridge in participating in a ceremony of remembrance for Collier Friday morning. The tribute drew about 1,600 people to the North Court of MIT’s campus, near the site of the shooting.
At the ceremony, MIT unveiled plans to build a permanent memorial at the site of the shooting, where there is now a temporary tribute.
The design was inspired by the gesture of an open hand and made up of five radial walls that meet at a center, said J. Meejin Yoon, an associate professor in MIT’s architecture department.
The design is meant to convey unity with the walls, made of solid granite blocks, buttressing a hollow space in the center, according to Yoon.
Two inscriptions are planned. One reads: “In the line of duty, Sean Collier April 18, 2013.”
Another is from a eulogy delivered by Collier’s brother, Robert Rogers: “Live long like he would. Big hearts, big smiles, big service, all love.’’
The memorial will transform “a site of tragedy into a site of reflection,” Yoon said.
About 25 members of Collier’s family attended the event, as did Officer Richard Donohue, an MBTA Transit Police officer who was wounded during a gunfight with the bombing suspects in Watertown. Donohue and Collier graduated together from the police academy.
The ceremony was followed by a picnic and rally for the MIT Strong team running Monday to honor Collier and raise money for a memorial fund that bears his name.
Collier was the fourth person allegedly killed by the Boston Marathon bombers.
On April 15, 2013, brothers Tamerlan and Dzhokhar Tsarnaev allegedly set off two bombs near the Marathon finish line that killed three people and wounded 260 others. Three days later, authorities released surveillance pictures of the two men believed to be involved in the bombings, the Tsarnaev brothers. Collier was attacked at about 10:20 that night.
The fatal shooting of Collier drew a small army of law enforcement officers into Cambridge and then Watertown, where Tamerlan Tsarnaev, 26, sustained fatal injuries in a furious gun battle with police.
The second bombing suspect, Dzhokhar Tsarnaev, who was 19 at the time, was captured hiding in a boat stored in a Watertown yard hours later. He has pleaded not guilty to 30 federal charges. Federal prosecutors are seeking the death penalty. He also faces state charges in Collier’s killing.
Sara E. Ferry, an MIT graduate student and a friend of Collier’s, said he was taken “in a moment of extreme evil.’’
“That instant has never defined how we remember him,” she said. “When Sean left, love rushed in.”
MIT Police Chief John Di- Fava grew close to Collier during the 15 months the young officer worked with the small department. Collier was about to leave to join the Somerville police force when he was shot.
With tears in his eyes and his voice shaking with emotion, DiFava recalled how he had heroes while growing up — the Lone Ranger, Ted Williams, Martin Luther King Jr.
But then he came to know Collier, who DiFava called “wise beyond his years.’’
He then paraphrased a line from William Shakespeare’s play, “Julius Caesar,” saying “a coward dies many times, but a brave man only once.”
“While I understand the meaning of the statement, I do struggle with its logic. I ask myself, ‘Why do the brave have to die at all?’ Sean was truly one of the brave ones.”
DiFava concluded by returning to his heroes.
“I now know that heroes still walk on God’s earth.’’
John R. Ellement contributed to this report.