Crown sheet failure

It's possible it was a crown sheet failure (cab was blown off) The description , the exposed tubes and missing front side sheet and the apparent fact that the engine remained upright would indicate to me that the origin of the explosion was around the front .Crown sheet failure usually occurs when water sloshes back on a dry hot crown sheet .I was told that pressure expands at 20 psi per second when that occurs . Crown sheet failure usually results in the violent separation of the boiler from the frame , and crewmen rarely survive . An exception was a crown sheet failure of C&Sng #70 in downtown Golden in 1936 .The experienced crew sustained minor injurues(probably because the boiler went all the way through the cab) and the engine was repaired . Steam engines are dangerous and require constant good repair and vigilance .