The plane suddenly jolted shortly after takeover then felt like it was falling, said Stef Zamorano, who was flying to Las Vegas with her husband to celebrate his birthday.

In front of her, Zamorano saw a woman who wasn’t wearing her seat belt shoot up and out of her seat, her long hair flying in a tangled mess. The man seated next to her was clutching her arm, and she said the woman across the aisle was panicking.

“She was pretty much verbalizing how we all felt, saying, ‘I want to get off this plane. I want to be on the ground,’ ” Zamorano told The Associated Press.

Data from the flight tracking site FlightAware shows it dropped roughly 300 feet (91.44 meters) in 36 seconds.

The Federal Aviation Administration said the flight, Southwest 1496, was responding to an onboard alert about another aircraft in its vicinity. The FAA is investigating. Southwest said the crew responded to two alerts that required the pilot to climb then descend. The flight departed from Hollywood Burbank Airport just before noon.

Still in shock, Zamorano said she could hardly make out what the pilot was saying when he later addressed the passengers.

Another passenger, comedian Jimmy Dore, posted on X that the pilot mentioned a near miss.

“Pilot said his collision warning went off & he needed to avoid plane coming at us,” Dore posted.

The plane was in the same airspace near Burbank as a Hawker Hunter Mk. 58 just after noon local time, FlightAware shows. A Hawker Hunter is a British fighter plane. Records show it is owned by Hawker Hunter Aviation, a British defense contracting company. The company didn’t immediately respond to messages seeking comment.

Mike Christensen, an airport spokesman for Hollywood Burbank, said that neither the control tower nor the operations department, which tracks planes departing and arriving, have any record of the Southwest flight plunging in their airspace.

Southwest said the flight continued to Las Vegas, “where it landed uneventfully.” The airline said that it is working with the FAA “to further understand the circumstances” of the event.

This close call is just the latest incident to raise questions about aviation safety in the wake of January’s midair collision over Washington, D.C., that killed 67 people.