Delta Air Lines passengers may have been a bit confused last night, when their flight landed at the wrong airport in South Dakota. The National Transportation Safety Board is now investigating to figure out how the heck that happened.

Flight 2845 was heading from Minneapolis to Rapid City Regional Airport with 130 passengers onboard, the Associated Press reports, and was scheduled to arrive at 8:50 p.m.

Instead, the A320 touched down instead at Ellsworth Air Force Base at 8:42 p.m., an NTSB spokesman said. Ellsworth is about 10 miles north of the airport in Rapid City.

KEVN News reports that military personnel walked through the cabin while the plane was on the ground at the base, and passengers were instructed to keep their window shades down. According to Delta’s website, the flight eventually arrived at Rapid City Regional at 11:31 p.m.

Delta said in a statement that it contacted the passengers “and offered a gesture of apology for the inconvenience.”

In the meantime, the crew has been taken off duty while NTSB investigates.

“Delta will fully cooperate with that investigation and has already begun an internal review of its own,” the agency said in its statement.

NTSB says Delta plane landed at wrong airport [Associated Press]

Delta flight lands at Ellsworth by mistake [KEVN]