The words 'Dangerous Day Ahead' appeared in the last tweet sent by storm chaser Tim Samaras, just hours before he, his son Paul Samaras and chase partner Carl Young were killed while chasing the El Reno, OK tornado on May 31, 2013. Special recounts the chasing activities of the Samaras team, Weather's Mike Bettes and his Tornado Hunt team, and Juston Drake and Simon Brewer of Weather's Storm Riders, as they followed, recorded and reported on the deadly storm.