Thousands of homes and businesses were without power in East Texas on Monday after severe storms near Dallas ripped off roofs and downed power lines, part of a violent storm system that also left four people dead in Oklahoma and Arkansas.

At least one tornado was confirmed to have touched down in northern Dallas on Sunday evening, the National Weather Service said.

Monday afternoon, Texas Gov. Greg Abbott issued a disaster declaration for 16 counties.

No deaths or serious injuries were reported in or near Dallas, the city said in a news release early Monday. Fire-Rescue spokesman Jason Evans told the Associated Press, though, that three people were hospitalized with non-life-threatening injuries.

In Arkansas, which also saw severe thunderstorms, at least one person was killed when a tree fell on a home in Rogers, about 150 miles northwest of Little Rock, according to the Benton County Department of Public Safety.

Damage was also reported in Oklahoma and Missouri. Authorities say severe thunderstorms were responsible for the deaths of three people in eastern Oklahoma, two because of carbon monoxide poisoning and one from a fallen tree.

The Storm Prediction Center in Norman, Oklahoma, said areas of Alabama, Louisiana, Mississippi and Tennessee could see severe thunderstorms late Monday.

Around Dallas, as emergency crews assessed the extent of the storms' power, photos on social media showed that the twister damaged some buildings, breaking glass and downing trees. Most of the damage within Dallas appeared to be limited to the northwest.

Dallas Mayor Eric Johnson said the city was lucky this time.

“I think we should consider ourselves very fortunate that we did not lose any lives – no fatalities and no serious injuries – in last night’s storms. I think we should all be very grateful for that,” Johnson said.

A Home Depot had its roof torn off and part of the building collapsed. The store’s manager told KDFW-TV that he sent employees home early and shut down the store after seeing the forecast Sunday night.

One fire station also appeared to be significantly damaged with a collapsed roof and debris all around.

Evans said seven people escaped a structure that collapsed in northwest Dallas, but Dallas Fire-Rescue was searching to see whether anyone was left inside. WFAA-TV reported that a convenience store collapsed in the storm, but the clerk told the station that everyone who was inside made it out safely.

Nearly 100,000 customers were without power as of 9 a.m., and about half got it restored by the evening, according to electric utility Oncor.

Entergy, which serves parts of Arkansas, Texas and Louisiana, reported more than 7,000 outages. Most had power by Monday evening, according to the utility's outage tracker.

Three schools are closed indefinitely because of storm damage, Dallas Independent School District said. Students at another three schools will attend classes at another school while crews assess less extensive damage, the district said on Twitter.

October tornadoes are not common and cities are rarely hit, according to tornado scientist Harold Brooks of the National Severe Storms Laboratory in Norman, Oklahoma.

A study by Brooks last year found that only one-third of the most violent tornadoes hit communities of more than 5,000 people. The Dallas-Fort Worth metroplex has been hit at least three times in the past 25 years, he said.

Contributing: Kristin Lam, USA TODAY; The Associated Press