Three 'storm chasers' were among 13 people killed by tornadoes that rampaged through central Oklahoma in the United States on Friday, underscoring the high risk of tracking the twisters.
Tim Samaras, 55, founder of tornado research company Twistex, was killed in the Oklahoma City suburb of El Reno along with his son Paul Samaras, 24, and Twistex meteorologist Carl Young, aged 45.
Five tornadoes touched down in central Oklahoma and caused flash flooding just 11 days after a massive twister ravaged the Oklahoma City suburb of Moore destroying 1200 homes and killing 24 people.
Severe storms also swept into neighbouring Missouri, while Moore experienced only limited damage this time, Reuters reports.
Ten people including four children died in Oklahoma City and its suburbs, and three more died in Missouri. Hundreds of people have been injured, many as they tried to flee.
As usual, the storm chasers closely tracked the storm to measure its power, gather research and take video to feed the television and internet appetite for dramatic images.
In a field known for risk-takers, friends say Tim Samaras was a cautious professional whose driving passion was research.
He founded Twistex, based in Colorado, to collect temperature, humidity, pressure and wind-speed data with the goal of increasing lead times for tornado warnings. Some of his research was funded by the 18 grants received over the years from the National Geographic Society.
Meanwhile, heavy rain also left many areas flooded and about 91,000 homes are without power in Oklahoma.