those who planted this bomb on the packed subway car. the home made explosive detonated at 8:20am, ruthlessly targeting passengers going to work, children to school. >> literally within three seconds of putting your bag down, the doors just closing, we hear a loud explosion occur. >> i turned left and i saw the fireball surged toward my side. >> reporter: then, panic as people tried to escape. >> there was a woman underneath me, there was a lady saying i'm pregnant. this little boy his face got smacked into the step. there was just layers and layers of people screaming. >> people were just crushed and trampling each other, it was every man for themselves. >> reporter: on the platform, chaos, confusion. towards the back of the train, hushed passengers make their way out, exiting single file across the tracks. as emergency responders tending to the injured. i saw one woman being wheeled out on a stretcher. her legs were quite badly burnt and wrapped up in plastic and