Why deadly Oklahoma twister grew to a record width of 2.6 miles

The tornado that struck near the Oklahoma City suburb of El Reno on Friday has been upgraded to an EF5 strength — the strongest rating on the Enhanced Fujita scale. National Weather Service (NWS) storm surveyors also put the tornado’s path at a whopping 2.6 miles (4 kilometers) across at its widest point, making it the widest tornado on record. The tornado was part of an outbreak that hit the area around the Friday rush hour and endangered thousands of people on local highways. Three storm chasers were killed in the outbreak after a tornado picked up and destroyed their vehicle — an event that has caused some soul-searching in the chaser community.