At the time of the fire, the Caldecott tunnel complex consisted of three bores side-by-side, each 0.7 mi long (1.1 km).
The natural draft in the tunnel (and the 4.7% gradient) acted as a chimney encouraging the smoke to flow uphill towards the oncoming vehicles and out of the (eastern) entrance portal.
Unknown to the people fleeing east in the tunnel, there were safe passages at intervals between the tubes; these might have enabled some victims to escape from the fire and smoke, but none of the unlocked doors available were used.
[citation needed] Killed Injured The Caldecott tunnel complex has a permanently staffed control room, and the vibrations from the initial crash were felt by those within it.
Unfortunately the valves that should have been used to divert the drainage outfall to a hazardous materials sump were corroded and non-functional, and the gasoline went into a nearby lake.
[citation needed] Firefighting at the site in the tunnel began at 1:30 am once the potentially explosive atmosphere at the lake was under control.
However, the heat of the fire had seriously affected the integrity of the tunnel firemain, and the water pressure was insufficient to support a hose stream.
In the absence of an effective means of fighting it, the fire was allowed to burn out and the remnants were extinguished with foam and dry powder.
The fire burned for between twenty-eight and forty minutes, during which time most of the 8,700 U.S. gal (33,000 L) of gasoline carried by the truck were consumed.
The tiles and grout on the walls of the tunnel were damaged and spalled by intense heat all the way to the entrance portal, 1,720 ft away (520 m).
The third tube of the tunnel was closed for repairs lasting a period of months; costs of the reconstruction project totaled more than $3 million.