Flash flooding caused by torrential rains killed five people in northern West Virginia and rescue crews were searching for three other people who were missing Sunday as authorities assessed damage to roads, bridges, natural gas lines and other infrastructure.

Officials said 2.5 to 4 inches (6 to 10 centimeters) of rain fell in parts of Wheeling and Ohio County within about a half hour on Saturday night.

“We almost immediately started getting 911 calls for rescue of people being trapped,” Lou Vargo, Ohio County’s emergency management director, said at a news conference Sunday. “During this time, we had major infrastructure damage to roads, bridges, and highways where we couldn’t respond to a lot of incidents. So we were delayed in getting there because there was just so much damage.”

Vargo added: “It happened so quickly and so fast. … I’ve been doing this for 35 years. I’ve seen major floods here in the city and the county. I’ve never seen anything like this.”

Authorities said vehicles were swept into swollen creeks, some people sought safety in trees and a mobile home caught fire.

Similarly, swift flash flooding arrived in Marion County, south of Wheeling and Ohio County, early Sunday afternoon, causing extensive damage to bridges, roads and some homes, the county’s Department of Homeland Security & Emergency Management said in a Facebook post. The county’s 911 line has already processed at least 165 calls for service since the storms began.

Gov. Patrick Morrisey declared a state of emergency in Marion County Sunday evening.

Jim Blazier, the fire chief in Wheeling in the state’s northern panhandle, said crews performed rescue operations into Sunday’s early morning hours. He said first responders regrouped Sunday morning and were focused on an area from the Ohio state line across the Ohio River to Wheeling Creek.

“We’re searching the banks, we’re searching submerged vehicles, any debris we find along the trail and so forth,” Blazier said. “We’re using drones, search dogs and swift water personnel, and we have teams organized that are searching sectors that we’re trying to recover anybody that’s missing.”

There were about 2,500 reported power outages in the county Sunday, Morrisey confirmed in a news release Sunday evening, which updated the number of people confirmed dead to five, with three more missing. He has declared a state of emergency in Ohio County and mobilized the National Guard to support emergency operations.

“In many respects, this is kind of a unicorn event, because a lot of the rain had very narrow areas and there were roughly 3 to 4 inches of water that fell in the area in less than an hour,” Morrisey said at a press conference earlier Sunday. “That’s very, very difficult to deal with.”

He added, “Your friends, your neighbors, your first responders and people in the community, they’re out working very hard to find people. That’s our No. 1 task right now, trying to identify anyone who may still be out there.”

The West Virginia rains followed heavy downpours in San Antonio on Thursday that killed 13 people. More than 7 inches (18 centimeters) of rain fell over a span of hours in the Texas city, causing fast-rising floodwaters to carry more than a dozen cars into a creek.