By Donna Leinwand Leger and William M. Welch, USA TODAY
CAMBRIDGE, Mass. - A Massachusetts Institute of Technology campus police officer was shot and killed Thursday night at the school's campus, authorities said, triggering a massive display of police force in the Boston area.
A short time after the MIT shooting, police reported exchanging gunfire with alleged carjackers in Watertown, a city next to Cambridge.
The shootings came as the entire Boston metro area was on high alert following Monday's fatal bomb explosions during the Boston Marathon and as the FBI was leading a massive manhunt for suspects.
It was not known if the Watertown events were related to the MIT shooting or the fatal explosions earlier in the week, but police response was massive with armored SWAT-type vehicle present.
Video from WCVB-TV showed police officers with guns drawn and apparently giving orders to a man face down on the street in Watertown.
At the scene in Watertown, an explosion could be heard, and police ordered journalists and spectators to move far back.
"I heard sirens, then a ton of gunshots.,'' said Adam Healy, 31, a behavioral specialist for autism who lives less than a mile from the scene. "And then I heard an explosion amid the gunshots. After the explosion, the sky lit up. "
Dan MacDonald, 40, sitting in a second story Watertown apartment, said he first heard sirens, then gunshots.
"It was about 10 to 15 shots. then there was an onslaught," he said. "There were 25 to 60 shots within 45 seconds. Then the shots stopped and boom. It was like dynamite."
Stephanie Guyotte, spokeswoman for the Middlesex District Attorney's office, said the situation in Watertown was still unfolding and she had no information on the suspects.
Police in Cambridge, where the school is located, issued a pair of Tweets saying that a campus officer reported shot around 10:30 p.m. had died.
"Police, DA Investigating Fatal Shooting of Campus Police Officer In Cambridge,'' the department Tweeted.
A Cambridge police officer confirmed the officer was shot but provided no other information.
There was a large number of Massachusetts State Police and officers from other agencies, as well as at least four fire trucks, at the scene on the campus.
Massachusetts State Police said it was assisting Cambridge and campus police in their investigation.
State police said no one had been arrested.
MIT campus police referred a caller to the campus news bureau, where no one answered calls.
State police spokesman Dave Procopio said the shooting took place about 10:30 p.m. local time outside an MIT building. The injured officer was described as a male but no further information about him was released.
Procopio says authorities are searching for a suspect or suspects.
About 11,000 people attend the prestigious school. The MIT campus is in Cambridge, just across the Charles River from Boston and less than two miles from Copley Square, where two bombs exploded Monday near the finish line of the Boston Marathon, triggering a massive manhunt for what the FBI said were two suspects.
The school posted a statement on its website saying only that there had been gunshots heard near the Stata building on campus. It said the area was cordoned off by police and urged students to stay away from the area.
"At 10:48 PM today gunshots were reported near Building 32 (Stata) which is currently surrounded by responding agencies. The area is cordoned off. Please stay clear of area until further notice. Unknown if injuries have occurred.. Although the situation is considered active and extremely dangerous, an investigation is underway. Updates will be provided at this site when more information becomes available."
The Cambridge police posted a statement on Twitter that they do not have a suspect in custody.
MIT issued a Tweet saying the investigation was continuing and warning: "Stay vigilant, stay indoors and away from Building 32/76 (Stata/Koch).''
Contributing: Melanie Eversley and Yamiche Alcindor in Boston