Sept. 5, 1910: At 10:30 p.m., a series of blasts destroyed the Lucas Bridge and Iron Co. plant, a nonunion firm in Peoria, Ill. "Three explosions reduced the building to kindling wood and four buildings adjacent to the property were wrecked,” The Times said. And for the second time in several weeks, a bomb in the East Peoria rail yards destroyed carloads of steel girders intended for a Peoria and Pekin Union railroad bridge that was being built over the Illinois River.

Despite the devastation, this incident provided a crucial lead to the identity of the bombers. Several days later, investigators found a an unexploded time bomb hidden in the railway bridge. It too had been set for 10:30 p.m. but malfunctioned.

For the first time, investigators could examine the bomb components, and they began trying to trace the alarm clock and the unusual type of can used for the nitroglycerin.