NOAA's preliminary estimate is that there were 288 tornadoes during the entire outbreak from 8:00 a.m. EDT April 26 to 8:00 a.m. April 28, 2011.

• During the 24-hour period from 8:00 a.m. EDT April 27 to 8:00 a.m. EDT April 28, The National Weather Service (NWS) estimates there were a total of 211 tornadoes.

• NWS issued outlooks five days in advance, watches hours in advance, and tornado warnings with an average lead time of 24 minutes. NWS issued warnings for more than 90-percent of these tornadoes.

• The largest previous number of tornadoes on record in one event occurred from April 3-4, 1974, with 148 tornadoes.

Expert NOAA analysis of the fatality information indicates that at least 344 people were killed during the entire outbreak from 8:00 a.m. EDT April 26 to 8:00 a.m. April 28. There were 334 fatalities during the 24-hour-period from 8:00 a.m. April 27 to 8:00 a.m. April 28.

• This is the most people killed by tornadoes in a two-day period since April 5-6, 1936, when 454 people were killed, mostly in Tupelo, Miss. and Gainesville, Ga.

• This is thedeadliest single day for tornadoes since the March 18, 1925, tornado outbreak that had 747 fatalities across 7 states (including the Tri-State Tornado). 

• The Tuscaloosa-Birmingham tornado during the April 2011 event caused at least 65 fatalities.

• These are the most fatalities from a single tornado in the United States since May 25, 1955, when 80 people were killed in a tornado in southern Kansas with 75 of those deaths in Udall, Kan.

• The deadliest single tornado on record was the Tri-State tornado (Missouri, Illinois, Indiana) on March 18, 1925, when 695 died.

Note: All numbers are based on combined NOAA and historical research records and current fatality estimates. The historical research records extend back to 1680.