A power outage Saturday evening at Baltimore-Washington International Thurgood Marshall Airport grounded a number of flights and left travelers in the dark.

The power went down at about 5:30 p.m., according to Jonathan Dean, BWI’s communications director. Power returned at the airport around 7:10 p.m., but it was not immediately clear what caused the outage.

“We apologize to our customers and appreciate their patience as we work to restore power throughout the airport terminal,” Dean wrote in an email.

The airport, on its website, advised travelers to confirm their flight status, because delays are possible.

A Baltimore Banner reporter at the airport said a pilot announced the outage was affecting the terminal and control towers and flights were grounded. It was unclear what caused the outage.

Alicia Strohl Resnicoff, a former assistant U.S. attorney and current Democratic strategist, posted on X, formerly Twitter, that she was stuck on the tarmac at the airport.

“The entire airport has lost power: no lighting or AC and it is sweltering. More concerning: the air traffic control tower is being evacuated bc the emergency generators are not working,” Resnicoff wrote.

Traveler Kristen Lynch posted on X that the temperature was rising inside the terminal and lines were static.

“It’s getting hot and unclear whether anyone in security line will make our flights womp womp,” Lynch wrote.

Tom Campbell, a traveler at BWI on Saturday, posted on X: “Stuck on the tarmac for an hour or so now. Just trying to get home to see the damage on my house in Houston that won’t have power for another week.”

The outage took out the air-conditioning system at the airport, where the temperature at 6:15 p.m. was 92 degrees.