At least 11 people have died due to extreme weather in the U.S., the Associated Press reports. Two first responders were killed and another was critically injured in Lubbock, Texas, on Saturday morning after they were hit by a vehicle while working the scene of a traffic accident in icy conditions, officials said. The Associated Press reports that Police Officer Nicholas Reyna, 27, died at the scene and Firefighter Lt. David Hill, 39, was taken to a local hospital where he later died. Another man died Friday night when a car flipped into a creek in Dallas, Texas. The Oklahoma Highway Patrol said 58-year-old Randall Hyatt drowned after he was swept away by floodwaters while getting out of his stalled truck.

In Iowa, a semi-trailer overturned in icy conditions and killed a passenger in the truck, according to the Iowa State Patrol. The National Weather Service in Birmingham, Alabama, said three people died in Pickens County. The Alabama Emergency Management Agency said the deaths were due to an “embedded tornado within a long line of intense thunderstorms.” Earlier on Saturday, the bodies of an elderly couple were found near a demolished mobile home in Louisiana, and another victim was killed by a falling tree in the Bossier Parish in the northwest part of the state. The National Weather Service also issued rare winter tornado warnings in Mississippi. Hundreds of thousands of people are without power stemming from the storms, the AP reports.