In Pictures: Tornadoes hit number of US states leaving areas 'like a warzone'
A vicious storm has torn through the western outskirts of a US city, spawning one or more tornadoes that downed trees and power lines, damaged homes and injured at least 12 people.
The storm hit Kansas City in the latest barrage of severe weather that saw tornado warnings as far east as New York City.
Parts of Pennsylvania and New Jersey also were under tornado warnings hours after a swarm of tightly-packed twisters swept through Indiana and Ohio overnight, smashing homes and blowing out windows.
One person was killed and at least 130 were injured.
Those storms were among 55 twisters that forecasters said may have touched down on Monday across eight states stretching eastward from Idaho and Colorado.
The past couple of weeks have seen unusually high tornado activity in the US, with no immediate end to the pattern in sight.
Tuesday offered no respite, as a large and dangerous tornado touched down on the western edge of Kansas City, Kansas, late in the day, the National Weather Service office reported.
Twelve people were treated for storm-related injuries at Lawrence Memorial Hospital on Tuesday night, spokeswoman Janice Early said. None of the injuries appeared to be life-threatening.
Kansas City International Airport temporarily suspended flights and forced travellers and employees to take shelter in parking garage tunnels for about an hour.
A powerful twister also touched down in the nearby township of Pleasant Grove, Kansas, seriously damaging homes.
But the severe weather was not limited to the Midwest. Tornadoes were confirmed in eastern Pennsylvania and the National Weather Service issued a tornado warning for parts of New York City and northern New Jersey.
The winds peeled away roofs, knocked houses off their foundations, toppled trees, brought down power lines and churned up so much debris that it was visible on radar.
Highway crews had to use snowploughs to clear an Ohio interstate.
Some of the heaviest damage was reported just outside Dayton, Ohio.
"I just got down on all fours and covered my head with my hands," said Francis Dutmers, who with his wife headed for the basement of their home in Vandalia, about 10mi outside Dayton, when the storm hit with a "very loud roar" on Monday night.
The winds blew out windows around his house, filled rooms with debris and took down most of his trees.
In Celina, Ohio, 82-year-old Melvin Dale Hanna was killed when a parked car was blown into his house, Mayor Jeffrey Hazel said Tuesday.
"There's areas that truly look like a war zone," he said.
Monday marked the record-tying 11th straight day with at least eight tornadoes in the US, said Patrick Marsh, a Storm Prediction Centre meteorologist. The last such stretch was in 1980.
Outbreaks of 50 or more tornadoes are not uncommon, having happened 63 times in US history, with three instances of more than 100 twisters, Mr Marsh said.
But Monday's swarm was unusual because it happened over a particularly wide geographic area and came amid an especially active stretch, he said.
As for why it's happening, Mr Marsh said high pressure over the south-east and an unusually cold trough over the Rockies were forcing warm, moist air into the central US, triggering repeated severe thunderstorms and tornadoes.
Scientists say climate change is responsible for more intense and more frequent extreme weather such as storms, droughts, floods and fires, but without extensive study they cannot directly link a single weather event to the changing climate.