Officer O'Leary was electrocuted when he attempted to move a downed powerline after a storm.

On September 29, 1906 at about 5 pm, Officer O'Leary was walking his beat the Tower Grove Park neighborhood after a storm that had thrown various parts of the city into darkness with downed power lines. Officer O'Leary discovered a downed electrical wire at 4311 Hunt. He first attempted to move the powerline with a stick, one of which was spluttering in the mud. The wire remained stuck in the mud and for some reason he attempted to move the wire after donning a pair of borrowed gloves from a citizen. When he grabbed onto the line he was electrocuted and died immediately.

Officer O'Leary, born in Ireland, had been with the department for four years and was assigned to Magnolia Avenue Station. He was survived by his wife and child. Interred: Calvary Cemetery, St Louis, MO.