"They kept making announcements on the loud speaker that it was just a drill and there was nothing to worry about," Coach Ali Stevenson told Local 15. "It seemed like there was some sort of threat, but they kept telling us it was just a drill."
Stevenson had just finished the marathon. His wife had been sitting in one of the seating sections where an explosion went off, but thankfully she left her seat and was walking to meet up with him.
"There was just smoke, another explosion went off," Stevenson said. "We all started running. There were people crying."
Stevenson said there was no question in his mind that this was an intentional act.
Comment: Update 16 April 2013
Local15TV have added the following details from Stevenson's testimony:
Stevenson said he saw law enforcement spotters on the roofs at the start of the race. He's been in plenty of marathons in Chicago, D.C., Chicago, London and other major metropolitan areas but has never seen that level of security before.
"Evidently, I don't believe they were just having a training exercise," Stevenson said. "I think they must have had some sort of threat or suspicion called in."