. >> but firefighter colin townsley spots something he believes is dangerous. he calls firefighters above ground, asking for more equipment and saying, people are in danger. >> he, through his experience, had seen something going on above the fire, wherever he could see, he knew something bad was about to happen. >> on the train platform below, passengers are now being urged to get out. the quickest escape route is up another bank of escalators near the fire. these, too, lead directly to the ticket hall. >> as soon as we got near the top, we noticed it was really dark and smoky. >> at that time, there was this policeman with a flashlight saying, hurry up, don't just stand there. >> but the warning comes too late. >> as soon as i went through that turnstile, some kind of explosion happened. >> when i was halfway up that escalator, a sheet of flame erupted and shot across the top of the hall of the top of the exit from that escalator. i was moving up toward a wall of fire. >> searing flames rip up the escalator and into the ticket hall, incinerating everything in