A massive winter storm dumped sleet, freezing rain and snow across much of the U.S. on Jan. 25, bringing subzero temperatures and halting air and road traffic. Tree branches and power lines snapped under the weight of ice, and hundreds of thousands of homes and businesses in the Southeast were left without electricity.

The ice and snowfall were expected to be followed by very low temperatures lasting for several days, which could cause “dangerous travel and infrastructure impacts,” the National Weather Service said.

Heavy snow was falling from the Ohio Valley to the Northeast, while “catastrophic ice accumulation” threatened from the Lower Mississippi Valley to the Mid-Atlantic and Southeast.

“It is a unique storm in the sense that it is so widespread,” weather service meteorologist Allison Santorelli said. “It was affecting areas all the way from New Mexico (and) Texas, all the way into New England, so we’re talking like a 2,000-mile (3,200-km) spread.”

President Donald Trump approved emergency declarations for at least a dozen states by Jan. 24. The Federal Emergency Management Agency had rescue teams and supplies in numerous states, Homeland Security Secretary Kristi Noem said.