As the air horn sounded at 7 this morning and about 8,800 runners bounded across the starting line of the ninth Run to Remember, MIT Police Sergeant Dave O’Connor stood by in uniform watching.
The half-marathon and 5-mile races, dedicated to law enforcement officers killed in the line of duty, drew police officers, military personnel, and civilians who gathered to honor the first responders to the Boston Marathon bombings and MIT Police Officer Sean A. Collier, shot and killed in his squad car the night of April 18, allegedly by the bombing suspects.
For the first time, registration for the race exceeded its 10,000 capacity, with 10,800 runners signing up and an estimated 8,800 making the run, according to race director Steve Balfour.
“These events are what’s keeping us on our feet right now,’’ O’Connor said. “Since the night of Sean’s death, the Massachusetts community has taken us into its arms … The Massachusetts community, the whole US community, have no idea what events like this do to keep us together.’’
Collier had told friends he wanted to register for the race, which starts outside the Seaport World Trade Center and circles Downtown Boston, then runs across the Longfellow Bridge and down Memorial Drive in Cambridge before looping back.
Balfour, whose father was among the founders of a memorial race for fallen police officers in Melrose and Wakefield 13 years ago, said organizers expected to reach capacity, but not as quickly as they did. Registration closed in April for the run,which benefits the Boston Police Runners Club children’s programs.
Usually, about 200 people register every week as the race nears, Balfour said. This year, about 3,000 signed up in the week after the Boston Marathon.
“An hour after the bombing in the Marathon registration starting clicking,’’ Balfour said.
More runners signed up after Collier was killed and his friend, MBTA Transit Police Officer Richard “Dic’’ Donohue, badly wounded in the manhunt for the bombing suspects.
Chicago Police Officer Kyleen Cowie flew in to Boston Friday with a team of about 30 runners from her department — most of them officers, some civilians and family members.
Cowie, who had never been to Boston before, ran the 5-mile race.
“It was a very emotional, but good run,’’ she said. “It’s a beautiful, beautiful run, a beautiful city.’’
Chris Ducar of Brookline pinned a race bib with Collier’s name and MIT police badge number, 179, to the back of his white shirt before the race. He had run the half-marathon three times before and registered after this year’s Marathon bombings, assuming the race spots will fill quickly.
His family members and friends, who have come in previous years to cheer him on, were not with him this year.
“After seeing all the security, it’s maybe easier that they didn’t come,’’ Ducar said.
Security personnel checked the bags of people entering the area around the starting and finish lines, and runners were told to keep their belongings in clear plastic bags.
Volunteers precisely directed the flow of runners around the Seaport World Trade Center before and after the race, making sure nobody but runners, volunteers, and a few supporters entered.
Police Commissioner Edward F. Davis, who briefly spoke to runners before the race, said he is working to make heightened security the norm at large events.
“This is usually a very low-key security event,’’ Davis said, “but this year’s security is increased.’’