We forget how much thermal energy lives in things like butter and flour. Butter has roughly the same energy by mass as high-grade coal. But who ever sees a truck full of butter as a fire hazard?

https://en.wikipedia.org/wiki/Mont_Blanc_Tunnel_fire (1999, 39 dead)

>> The fire burned for fifty-three hours and is estimated to have reached a temperature of 1,000 °C (1,830 °F), mainly due to the margarine load in the trailer, equivalent to a 23,000-litre (5,100 imp gal; 6,100 US gal) oil tanker