The time that it took from the first signs of disaster to the bow crashing to the ground is often reported as 32, 34 or 37 seconds. Since none of the newsreel cameras were filming the airship when the fire first started, the time of the start can only be estimated from various eyewitness accounts and the duration of the longest footage of the crash. One careful analysis by NASA's Addison Bain gives the flame front spread rate across the fabric skin as about at some points during the crash, which would have resulted in a total destruction time of about 16 seconds (245m/15 m/s=16.3 s).