updated 04/19/2013 AT 1:40 PM ET
•originally published 04/19/2013 AT 3:30 PM ET
Now, many of those same heroes are trying to reunite with those they helped to see if they’re okay.
Matt Patterson, 30, an off-duty firefighter from Lynn, Mass., north of Boston, is among those looking to reconnect after helping to save a little boy who lost a leg in the bombings.
A veteran of the war in Afghanistan, Patterson was in a nearby restaurant when the first bomb went off. “I knew it was bad when I heard it,” he tells PEOPLE. “Anybody who served knows that feeling. I knew it wasn’t right. It’s a very specific sound.”