Supposedly 25th March, A.A.Anderson photos taken the "morning after" dated 26th March 1935 shown in several books and directly noted in Klinger's High Line Memories pg 40>42
Mondays and Wednesdays were "Train Days" at Como, with freights from both Denver and Leadville in town.
Some accounts speculated #72 having ignited a bird nest, but most of the railroaders put the blame on "Jonah" #75.
The photo taken over the rotary cowling shows #72, having been pulled forward, still sporting the box headlight which was replaced with the small Pyle headlight when returned to service.