At least two people were killed and several more injured after Tuesday’s severe thunderstorm and possible tornadoes struck the Danbury area, uprooting trees and knocking down power lines.

The damage to the area was so extensive some towns were urging residents to stay indoors Wednesday and school closures were announced for most local districts.

The downed trees and wires snarled the evening commute, blocking side roads, as well as portions of major roads, such as Interstate 84 and Route 7.

State Police said a person was killed when a tree fell on their car on Brush Hill Road in New Fairfield.

A man was killed while doing yard work at his home in the Candlewood Lake area, Danbury Mayor Mark Boughton said late Tuesday night. He said the man went into his truck while doing yard work and a tree fell on the truck.

The names of the deceased were not immediately released.

Boughton said another person is at Danbury Hospital after being seriously injured at Henry Abbott Technical High School. He said the roof flipped off the building and hit someone on a nearby field. He was unable to say whether the person hit was a student or athlete.

“They’re in very serious condition,” Boughton said. “We’re hoping they’ll pull through.”

In Brookfield, a woman was seriously hurt while walking on the Still River Greenway, according to Brookfield First Selectman Steve Dunn.

Ridgefield First Selectman Rudy Marconi said Region 5 of the Emergency Management and Homeland Security was hit the hardest by the storm. He is the chairman of the agency comprised of 43 towns that make up the region, which spans from Ridgefield north to Massachusetts and from the New York state line to Waterbury.

“The area just north of Ridgefield really took it on the chin,” he said. “I’m really hoping lives are spared. The possibility of fatalities is greater than one would like to admit.”

Brookfield resident Stan Strauss was in his garage working with his wife on their tractor Tuesday afternoon when the sky suddenly turned dark.

Within minutes, the heavy rain started and the wind howled, bringing down several of the ancient trees that sit on their nearly 2-acre property on Junction Road in Brookfield, including on the garage the couple became trapped in. Strauss’ wife was hit in the head by a piece of the structure before the couple sought shelter in the car parked in the garage.

“It looks like a bomb hit us,” Strauss said.

Thousands of customers were without power and many roads were closed due to downed trees and wires. Reports came in of trees on cars with people trapped inside in Danbury, Bethel, Brookfield and New Milford.

At one point, all of Southbury’s 9,923 customers were without power, as well as 95 percent of New Fairfield customers and 77 percent of Newtown customers. More than 10,500 outages were reported in Danbury and more than 2,600 in New Milford, about 2,000 outages in Bethel and nearly 1,700 outages in Redding and Ridgefield.

All of the Danbury area schools announced Tuesday night they would be closed Wednesday, with Region 12 opening on a two-hour delay. Brookfield town offices also closed.

Western Connecticut State University opened a shelter in the Bill Williams Gymnasium at the midtown campus for those without power and who may need to use medical devices.

Although Danbury Hospital is open and operational, the Western Connecticut Medical Group warned of possible delayed openings at some of its primary care, specialty and testing/images offices.

In Brookfield and New Milford, officials declared states of emergency, which allows for additional emergency resources and equipment.

“There was significant damage in the southern part of New Milford, from Candlewood Lake to Brookfield,” New Milford Mayor Pete Bass said. He said fire crews are walking door to door in these areas to ensure the homes and people are safe because the roads are impassable.

Ryan Gallagher, a meteorologist with Connecticut Weather Center, said he estimated winds reached 60 mph in Danbury.

Gallagher said there are indications that a tornado touched down in parts of New Fairfield and southern New Milford, which is consistent with damage along Candlewood Lake. But Gallagher said this can’t be confirmed until the National Weather Service comes out to check, which would likely occur Wednesday morning at the earliest, based on the amount of damage reported.

He said the peak storm season in Connecticut is usually in June and July. But the conditions aligned for the storm with an unstable air mass moving in from Pennsylvania and then the afternoon sun weakening the lower air, allowing the front to come in, he said.

“It was like dominoes,” Gallagher said. “It was two different types of dangerous winds.”

He said the severe storm passed through the area in 10 to 20 minutes and the thunderstorms left in the area were residual.

Metro-North and Housatonic Area Regional Transit temporarily suspended service.

In Brookfield, results for the day’s budget referendum were delayed due to the town’s power outages.

First Selectman Matt Knickerbocker reported damage throughout Bethel. He said the highway department has at least three pages worth of partial road blockage reports detailing roads to clear.

“Everyone is gridlocked,” Dunn said. “Every road I’ve driven on has trees across it, so the entire town has problems.”

Staff writers Tara O’Neill, Anna Quinn and Julia Perkins contributed to this story.