The Federal Aviation Administration said it’s investigating an extremely close call between two Southwest Airlines flights at Nashville International Airport.

At their closest point, the planes were right on top of one another, with the vertical separation between the two planes at just 500 feet, according to FlightRadar24.

The incident unfolded at about 5:30 p.m. Saturday. Southwest Flight 507 was about to land in Nashville amid gusty winds when the pilots “executed a precautionary go‑around,” Southwest Airlines said.

During the go‑around, the pilots “received instructions from air traffic control” that put the plane in the path of another Southwest flight that was taking off from a “parallel runway,” the FAA said in a statement.

Pilots on both Southwest planes responded to onboard alerts, the FAA said.

“There are multiple alarms that can go off in the cockpit,” ABC News contributor and retired Marine Col. Steve Ganyard explained. “In this case, it was the most serious of those alarms, telling those pilots, you’re on a collision course, you need to move the airplane now.”

Flight 507 landed uneventfully after the go-around and Flight 1152 continued with its takeoff, Southwest said.

“Southwest appreciates the professionalism of its Pilots and Flight Crews in responding to the event,” the airline added. “Nothing is more important to Southwest than the Safety of our Customers and Employees.”