BOSTON (WWLP) - The impact of the explosion is far reaching and authorities continue to gather more information.
Authorities continue to comb through a massive area that's about 15 blocks, in, around and along the marathon route.
Three people were killed and more than 150 have been hurt. Early Tuesday, Boston Police Commissioner Edward Davis said they've gathered surveillance footage from businesses in the area and plan to review those frame by frame.
They've also appealed to the public asking them to send any video of photos they may have captured moments before the explosion.
To find out how to submit any photos or videos of the Boston Marathon explosion call 1-800-494-TIPS (8477).
So far authorities are not confirming what type of explosive it was or how it was detonated, but during the news conference earlier Tuesday, the chief trauma surgeon at Mass General said many of the victims have shrapnel and nails lodged into their bodies. He said they didn't seem to be part of the environment around them but rather something that came off the explosive.
This heightened security has had a big impact not only on the businesses, but people who live in Boston area.
According to a letter sent to students by Emerson's President Lee Pelton, seven students were injured during the explosion. They have been treated and released.
There were no classes at Emerson College Tuesday; the campus was closed to provide a day of healing and reflection. Suffolk University was open as Bostonians try to get back to a sense of normalcy. One of which they won't get for a while.