Heavy rains swept through Dallas on Tuesday night and early Wednesday, triggering flooding across the region.

At Dallas Love Field Airport, travelers returning to their cars at two underground parking garages had an unwelcome surprise: Dozens of their vehicles were submerged in floodwater.

The water rose to the roof of many vehicles. According to the NBC affiliate in Dallas, flooding affected two garages, A and B. “The parking garages looked like ponds with crosswalks completely flooded,” the affiliate reported.

On Wednesday morning, crews were working to pump the water out. Dallas Love Field spokesman Chris Perry told Dallas’s CBS affiliate that the flooding was the result of an off-site drainage issue.

In addition to the inundation of the parking garages, flooding forced 20 high-water rescues in the Dallas region, according to the Fort Worth Fire Department. The department tweeted that it responded to 45 weather-related incidents in three hours Tuesday night.

Severe thunderstorms moved into the Dallas area just after 9 p.m. central time Tuesday. Dallas Fort Worth International Airport clocked a 60 mph wind gust as the storms came through.

Rainfall totals of at least two to four inches were widespread. Dallas Fort Worth International posted 3.22 inches through Wednesday morning, while Dallas Love Field checked in with 3.55 inches.

More showers and thunderstorms capable of producing heavy rain are forecast for the Dallas region on Wednesday, and a flash flood watch remains in effect until midnight.

The rain is the result of a slow-developing area of low pressure in South Texas that is drawing moisture from the Gulf of Mexico over large parts of the state. The low-pressure zone is forecast to finally exit Texas early Thursday before heading northeast toward the Ohio Valley on Friday and into eastern Canada over the weekend.