New Zealand investigators on Tuesday seized the flight recorder from a Boeing-made LATAM plane to determine what caused it to plunge and injure dozens of passengers.

The Boeing 787 Dreamliner was en route from Sydney to Auckland on Monday evening when it lurched earthward without warning, slinging some unrestrained passengers out of their seats and smashing others into the cabin ceiling.

“Everyone started screaming, crying,” said Australian receptionist Ellie Addison, one of 263 passengers aboard flight LA800.

“People were launched out of their seats, there was blood pouring from people’s faces.”

Sales administrator Veronica Martinez said it felt like the plane had stopped mid-air, and then “we just plunged.”

“People were flying, babies fell, it was horrible, lots of people were injured,” she told Agence France-Presse.

Emergency crews raced to Auckland Airport to meet the incoming flight, dispatching more than a dozen ambulances and other medical vehicles.

Support worker Gabriel Felipe de Oliveira Adaime said the flight was “traumatizing,” while fellow passenger Agustin Ramonda said it was “one of the worst three seconds of my life.”

Paramedics said they treated about 50 patients. Four people remained in hospital as of Tuesday morning, Health officials told AFP.

The flight arrived on time, LATAM said in a statement.

A pilot asked by a passenger of what happened told national broadcaster Radio New Zealand that he lost his instrumentation briefly and then it just came back all of a sudden.

Air accident safety investigator Joe Hattley told AFP that technical problems were rare in modern aircraft.

“That flight record will be key to understanding this event,” said the teacher at the University of New South Wales in Australia, referring to the seized black box.

“It will tell investigators if it was an atmospheric event or a technical problem with the aircraft.”