their goal was to create a computer simulation of the deadly fire using computation fluid dynamics, or cfd. this was the first time it would be applied to the behavior of fire, but they believed it would work because heat and air flow like fluids. >> the hot air causes the fluid to expand, and it makes it lighter, and then it tends to rise relative to the other ambient fluid around. and so, then you see smoke rising, smoke plumes, and that's the kind of thing that we can simulate with the software, because it really is just simple fluid mechanics. >> but could it solve the mystery of the king's cross fire? female announcer: time is running out to get the hottest deal on a new mattress. sleep train's 4th of july sale is ending soon. right now at sleep train, save $300 on beautyrest and posturepedic mattress sets. plus, pay no interest for 36 months on tempur-pedic and serta icomfort. big savings and interest-free financing? these deals aren't just hot... they're explosive! sleep train's 4th of july sale is ending soon. ♪ sleep train ♪ your ticket to a better night's sleep ♪ >>> to recreate