321 Lives Lost in 72 Hours: 15 Year Anniversary of The Most Violent Tornado Outbreak in History

It has been 15 years since one of the deadliest tornado outbreaks in U.S. history. The multi-day outbreak fired up on April 25, 2011, lasting through April 28. The outbreak was blamed for 321 fatalities, 2,775 injuries, and over $15 billion in total damage. The April 2011 rash of tornadoes and an outbreak in April of 1974 are the only two events to earn the designation of a "Super Outbreak." Here is a look back at this devastating stretch of days.

Volume and Timing of Tornadoes

Outside of being the costliest tornado outbreak in U.S. history, the sheer volume of the twisters is what made headlines in April of 2011. When all the dust had settled, meteorologists had confirmed 362 tornadoes over a period of just 72 hours. The Deep South was ground zero for the majority of the activity; however, tornadoes were reported as far as New York.

Four EF5 tornadoes were confirmed during the outbreak. The first of these monster twisters spun up in east-central Mississippi. This tornado was intense enough to rip asphalt up from a road and send it flying.

There were 303 tornado warnings issued by the six National Weather Service (NWS) offices most impacted on April 27. The NWS-Huntsville, Alabama, field office issued 90 warnings on this day. The six NWS offices boasted an average lead time of 20 to 22 minutes, despite the overall chaos of the day.