smoke quickly filled the busy subway corridor near times square. cnn's jason carroll joins us with more. what more details have you learned? >> reporter: well, let's first, anderson, talk about the device, or should we say devices that the suspect used. law enforcement sources tell cnn that there were actually two devices. one that detonated -- partially detonated. the other did not. the one that partially detonated was the one that, as you say, was attached to his body. it was a pipe about a foot long. it contained black powder, screws, it also contained nails, a battery. again, this was a device that partially detonated. no information on the second device. obviously, given where this happened, given the timing, in terms of when it happened, you can understand why law enforcement sources say this could have been much much worse. >> do authorities understand why exactly he chose the location he did to set off the device? obviously, it's a crowded time, in a busy place. >> reporter: there are a couple things. first of all, this is a suspect who worked nearby.