(WHTM) — Pennsylvania is no stranger to natural disasters. Fires, tornadoes, hurricanes, floods, and snowstorms can all be deadly and cause massive amounts of property damage.

But which of these natural disasters was the worst in the state?

The Johnstown Flood of May 31, 1889, was the worst natural or weather-related disaster in Pennsylvania. The flood was caused by the failure of the South Fork Dam. The failure happened due to an extreme amount of rain falling over the region within a 24-hour period.

The US Army Signal Corps estimated that six to 10 inches of rain fell throughout the Johnstown region, and this heavy rain caused the dam to completely fail, sending a wall of water that was more than 30 feet high.

The wall traveled 14 miles at speeds of up to 40 miles per hour. Before striking Johnstown, the wall of water hit South Fork, Mineral Point, East Connemaugh, and Woodvale which caused extreme damage in all of the communities. The dam contained 20 million tons of water before it gave way, about the same amount of water as goes over Niagara Falls in 36 minutes, according to the Johnstown Area Heritage Association.

Around 4:07 p.m. on May, 31, the wall of water hit Johnstown. According to the Pennsylvania Historical and Museum Commission, the water wiped out four square miles of the community within 10 minutes, which equated to roughly 1,600 homes and 280 businesses.

The flood swept several locomotives weighing 170,000 pounds as far as 4,800 feet. The damage was estimated to be around $17 million, which adjusted for inflation is around $300 million today. Flood lines were recorded to be as high as 89 feet above the river level.

According to the Johnstown Area Heritage Association, 2,209 people died and 99 entire families died, including 396 children. News of the flood spread throughout the United States and the world. Around $3.7 million was collected for the relief effort from both the US and 18 foreign countries.

Since the flood of 1889, Johnstown has also been hit with floods in both 1936 and 1977.