Three storm chasers were among the nine people killed in the most recent tornadoes to strike Oklahoma, CNN reports.
Tim Samaras, 55, and his 24-year-old son Paul died along with 45-year-old Carl Young whilst chasing a tornado in El Reno, relatives said.
Writing on Facebook, Jim Samaras confirmed that the trio had been killed:
Thank you to everyone for the condolences. It truly is sad that we lost my great brother Tim and his great son, Paul.
The men who died made a living from researching and recording extreme weather.
More top news
It will be a frosty start for many across the UK with slow-clearing mist and fog across parts of central and southeastern England.
The prime minister says she has proven the "doubters" wrong but still faces opposition from both sides of the Brexit line.
Defence saving plans raise "serious doubts" over the Ministry of Defence's ability to pay for new equipment, including warships and planes.