Reports are coming in that two explosions occurred today shortly after the first participants crossed the finish line of the Boston Marathon and while thousands were still taking part in the race. Around 2:45 p.m. EST, two thunderous booms near the marathon headquarters have caused officials and police to close and lock down the Fairmount Copley Plaza Hotel. The medical tent that had been setup to care for fatigued runners has been turned into a makeshift hospital tending to injured spectators.