This was not a Monon depot. This depot was wrecked by a train running out of control over the Wabash River bridge from West Lafayette, and didn't make the curve but slammed into the depot instead. This was replaced by a sturdy stone building, what is now known as the Big Four depot. (The Big Four depot in recent years was later moved down 2nd street, and is now serving as the Amtrak depot and Greyhound station). The current Social Security building is roughly where this depot was located.
The distinctive tower lasted longer than the station that was wrecked. It shows up as late as 1952-53 in some photos of NYC steam engines at that location. (See attached - sorry for low pic quality). In a nod to history, the top of one of the elevator towers at Riehle Plaza (to get Amtrak patrons over the tracks) is modeled on this tower.
--Ken Weller, Lafayette IN