ELLICOTT CITY, Md. -- Roaring flash floods struck a Maryland community Sunday that had been wracked by similar devastation two years ago. Ellicott City's Main Street turned into a raging river that reached the first floor of some buildings and swept away parked cars, authorities and witnesses said. There were no immediate reports of any injuries.

CBS Baltimore showed images of turbulent water rushing down Main Street -- the same area devastated by flash flooding in July 2016. That flood killed two people and destroyed local businesses.

Maryland Gov. Larry Hogan declared a state of emergency for the stricken area Sunday and traveled there for a firsthand look at the destruction.

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"The immediate focus is ensuring everyone is safe and secure," Hogan said in a statement. "I strongly urge all Marylanders to monitor the weather, heed all warnings, and avoid the affected areas."

Footage of Sunday's flash flooding showed the seething floodwaters engulfing cars and pickup trucks. The Howard County Fire & EMS agency tweeted that water was above the first floor of some buildings at the height of the disaster.

Fire rescue crews were going door-to-door to make sure residents were not trapped in lower-level buildings, CBS Baltimore reports.

Some residents of Ellicott City told The Baltimore Sun the flooding appeared to be worse than the 2016 flooding that killed two people and destroyed local businesses.

Jessica Ur, a server at Pure Wine Cafe, told the paper she watched as gushing waters swept three or four parked cars down the street. She had been around the last time the area flooded, but said this time it appeared worse.

"It's significantly higher than it was before," she told the newspaper, comparing the floodwaters to those of 2016.

Water rushes through Main Street in Ellicott City, Md., Sunday, May 27, 2018. Libby Solomon/The Baltimore Sun via AP

Some reported a blaring alarm had sounded. Others said they gathered in the second story of a building to anxiously watch the seething waters. One sight during the flood: a handmade, white flag hung from an upper story of a Main Street building bearing the letters SOS.

"If you are trapped, we are coming," the Howard County Department of Fire and Rescue Services tweeted at one point. It added that multiple rescues were carried out, and rescue swimmers were called in to help. The department also said swift water units from as far away as Northern Virginia were summoned.

Meanwhile, some roads were also flooded in neighboring Baltimore County. A spokeswoman in Baltimore County said the fire department has received dozens of calls about cars stuck in high water and flooded basements.

Ellicott City has been rebuilding since the 2016 flooding damaged and destroyed businesses. Local officials recently said that 96 percent of the businesses were back in operation and more than 20 new businesses had again opened in the Main Street area.

Just two weeks ago, Hogan announced that the Federal Emergency Management Agency had awarded the state and county more than $1 million to pay for projects aimed at reducing the flood risk in areas around Main Street.

On Sunday, officials opened a shelter at a community center in Ellicott City for the victims.

The disaster came on a day when the National Weather Service said a flash flood warning had been issued for what it described as an "extremely dangerous situation." A meteorologist said about 8 inches fell in Ellicott city in a six-hour period.