The Yarnell Hill Fire was a wildfire near Yarnell, Arizona, ignited by lightning on June 28, 2013. On June 30, it overran and killed 19 City of Prescott firefighters, members of the Granite Mountain Hotshots. It was the deadliest U.S. wildfire since the 1991 East Bay Hills fire, which killed 25 people, and the deadliest wildland fire for U.S. firefighters since the 1933 Griffith Park Fire, which killed 29 impromptu civilian firefighters. It was also the most fatal incident of any kind involving U.S. firefighters since the September 11 attacks, which killed 343. It is the sixth-deadliest American firefighter disaster overall and the deadliest wildfire ever in Arizona.