LATAM Airlines Flight 800 — a Boeing 787-9 Dreamliner — was stopping in Auckland before heading to its final destination in Santiago, Chile, according to local media reports and the flight tracking website FlightAware.

In a statement, the Hato Hone St. John ambulance service said its crews responded to an incident at Auckland International Airport involving an inbound aircraft Monday afternoon local time.

After seven ambulances and other vehicles and teams arrived at the scene, they “assessed and treated approximately 50 patients,” including one in serious condition and the remainder in moderate to minor condition, it said. Twelve patients were taken to a hospital to be treated for injuries, Hato Hone St. John said.

A passenger on board told Radio New Zealand that the flight was going smoothly until about two-thirds of the way into the roughly three-hour journey to New Zealand, when the plane “just dropped.”

The passenger, Brian Jokat, told the outlet that several passengers were thrown up to the ceiling of the plane, with some breaking parts of the cabin on impact and others injuring themselves when they hit the floor.

“Then people just started screaming. I felt the plane take a nosedive — it felt like it was at the top of a roller coaster, and then it flattened out again,” Jokat said. The entire incident lasted only “split seconds,” he said.