Preparedness Day bombing

Preparedness Day bombing
Part of terrorism in the United States
Location	Embarcadero, San Francisco, California, U.S.
Coordinates	37°47′39″N 122°23′40″W / 37.794167°N 122.394444°W / 37.794167; -122.394444
Date	July 22, 1916 2:06 p.m. (UTC−08:00)
Target	Preparedness Day Parade
Attack type	Bombing
Weapons	Time bomb
Deaths	10
Injured	40
Perpetrators	Undetermined
Motive	Opposition to World War I
Accused	Warren Billings Rena Hermann Thomas Mooney Ed Nolan Israel Weinberg
Convicted	Warren Billings Thomas Mooney (both later pardoned)
Verdict	Death, commuted to life imprisonment (later pardoned)

The Preparedness Day bombing was a bombing in San Francisco, California, United States, on July 22, 1916, of a parade organised by local supporters of the Preparedness Movement which advocated American entry into World War I. During the parade a suitcase bomb was detonated, killing 10 and wounding 40^[1] in the worst terrorist attack in San Francisco's history.

Two labor leaders, Thomas Mooney and Warren Billings, were convicted in separate trials and sentenced to death, later commuted to life in prison.^[2] Later investigations found the convictions to have been based on false testimony, and the men were released in 1939 and eventually pardoned. The identity of the bombers has never been determined.