Search teams on Sunday picked through wreckage left by tornado-spawning thunderstorms that swept the U.S. Southern Plains and Ozarks, killing at least 14 people and wrecking hundreds of buildings as forecasters warned of more severe weather over the holiday weekend.

In Indiana, storms delayed Sunday’s scheduled start of the Indianapolis 500-Mile Race, or Indy 500, the premier U.S. auto racing event traditionally held over the Memorial Day weekend.

At least seven people perished and nearly 100 were injured on Saturday night when a powerful tornado struck communities in north Texas near the Oklahoma border, Governor Greg Abbott said at a news conference the next day.

He said two children, aged 2 and 5 from a single family, were among the dead in and around the tiny Cooke County town of Valley View, which bore the brunt of the twister.

More than 200 homes and other structures were listed as destroyed, with another 120 buildings damaged in a zone that stretched over 50 miles, Abbott said.

Dozens of motorists abandoned their vehicles on a highway and fled to a nearby truck stop seeking shelter as the twister struck. According to Abbott, about 125 people took cover inside the gasoline station as the tornado shredded the facility.

Everyone there survived, but it took rescue teams about an hour to free scores who were trapped in the wreckage.

“I was just waiting for it to pick us up or slam something on top of us,” Elizabeth Hernandez, who had huddled inside a restroom in the building, recalled in an interview with Dallas television station WFAA. “I don’t know how that didn’t kill us.”

MOBILE HOMES ‘COMPLETELY GONE’

A National Weather Service official said the Valley View tornado packed top winds of 135 miles per hour. Multiple twisters hit the region, but the precise number had yet to be determined, she said.

As the scale of the disaster came into fuller view on Sunday, officials were wrapping up initial search-and-rescue operations, the governor said. He said authorities would make one final sweep of damaged buildings for possible additional victims but that nobody else was reported missing by day’s end.

Cooke County Sheriff Ray Sappington said some of the many trailer homes in the area were “completely gone” after the storm.

Video footage from the aftermath of the disaster showed wide swaths of homes and other buildings in shambles or reduced to piles of rubble, with vehicles smashed and trees uprooted or stripped of limbs and foliage.

A tornado also crossed into Denton County, northwest of Dallas, on Saturday night, damaging homes and other property, and knocking down power lines. Officials said that “a number of individuals” with injuries were transported to area hospitals.

More than 450,000 utility customers were without electricity across a 10-state region on Sunday stretching from Texas to Michigan, according to the website poweroutages.us.

Officials in Arkansas also reported at least three storm-related fatalities from late Saturday, including a 73-year-old woman in Baxter county. Responding authorities described roads closed and clogged with debris, downed trees and power lines, homes and businesses destroyed, as well as numerous injuries.

Storms caused widespread damage and at least two deaths on Saturday night in parts of Oklahoma.

On Sunday, as storms shifted to the northeast, unleashing more extreme weather across the U.S. heartland, a landscaper was killed by a tree toppled in winds that gusted to 80 mph in Louisville, Kentucky, police said.

The Weather Service warned of additional storms moving through the Ohio and Tennessee valleys, bringing a mix of damaging winds, large hail and more tornadoes, as well as heavy downpours capable of triggering flash floods.

As Texas residents struggled to regain their footing from a night of thunderstorms and tornadoes, excessive heat warnings and heat advisories were posted on Sunday across the southern tier of the state and along the Gulf Coast into most of Louisiana.

The latest bout of extreme weather came just days after a powerful tornado ripped through a rural Iowa town, killing four people, and more twisters touched down in Texas last week.

Meanwhile, the U.S. was preparing for what government forecasters have called a potentially “extraordinary” 2024 Atlantic hurricane season beginning June 1.