I knew an older SP Western Division engineman who had time on steam and he told me a story about leaving Fresno one morning on a 2-10-2 with a new fireman. Whatever he had for breakfast wasn't sitting real well in his gut and he finally had to stop right on the main line. After calling out the flag, he ran for a grove of trees and took care of the problem. When he got back, the kid fireman was gazing out the window and had left the Worthington FW pump running...all that cold water in the boiler made for a number of firebox leakers. They limped into BK, filed a delay and report. The engineer took some demerits and the fireman was never seen again.