1830: Shelbyville, Tennessee was turned into “a heap of ruins” as a tornado moved east through the center of the town. This tornado destroyed 15 homes and 38 businesses along with churches and other public buildings. Losses were estimated to be as high as $100,000. A book was said to be carried seven miles away.
1889: The Johnstown, Pennsylvania disaster occurred, the worst flood tragedy in U.S. history. Heavy rains collapsed the South Fork Dam sending a thirty-foot wall of water rushing down the already flooded Conemaugh Valley. The wall of water, traveling as fast as twenty-two feet per second, swept away all structures, objects, and people. 2100 persons perished in the flood.
— Johnstown Flood NPS (@JohnstownFldNPS) June 1, 2017
May 31, 1889 – the Great Johnstown Flood. Heavy rain lead to the failure of the dam and 20 million tons of water raced into Johnstown, PA. pic.twitter.com/BuggL6s8Nk
— NWS MARFC (@NWSMARFC) May 31, 2017
1985: 43 tornadoes tracked across Ohio, Pennsylvania, New York, and Ontario. Eight tornadoes were rated as F4s, and one was rated as F5. The Niles, Ohio to Wheatland, PA is Pennsylvania’s only F5 tornado.
Source: May 31, 1985: A tornado outbreak out of place – USTornadoes.com.
2013: The 2nd of the top 10 weather events for 2013 was EL Reno, Oklahoma tornado of May 31, 2013. Part of the multi-day storm outbreak caused $2 billion in damage. The EF3 that traveled through the western suburbs of Oklahoma City was the largest tornado ever observed with a width of 2.6 miles. It took eight lives including four tornado chasers.
Source: NWS Office in Norman, Oklahoma.