NTSB is sending an investigative team to an Amtrak derailment in Missouri that killed 3 people and injured at least 50

A team of National Transportation Safety Board investigators will arrive in Missouri on Tuesday to probe the derailment of an Amtrak train that left at least three people dead and sent surviving passengers scrambling from the wreckage.

The derailment occurred as the train, traveling eastbound to Chicago, collided with a dump truck at a crossing near the town of Mendon in north-central Missouri at about 12:42 p.m. Monday, according to Amtrak. Eight of the train's cars and two locomotives left the track, the company said.

"We started feeling the train tilting over to the right. That's when it kind of went through my mind that this is life or death. This is very serious," Dax McDonald, who was on the train with his sister Samantha, told CNN's "New Day."

Their train car had tipped over and was laying on its side. Samantha McDonald said she looked straight up and saw the windows that offered their only chance for escape.

"We had to climb 10 feet straight above us to the escape windows," she said. "I was able to lift myself up, and then there was other passengers that had gotten out before us from the other train cars that were able to help lift me up and our family," she said. "It was absolutely insane."

Preliminary reports indicate the crossing where the train hit the dump truck was "uncontrolled," meaning there were no lights or mechanized arms.

Two of the people who were killed were aboard the train while the third was in the dump truck, said Cpl. Justin Dunn, a spokesperson for Missouri State Highway Patrol Troop B.

At least 50 people were injured in the derailment, Chariton County Ambulance Service Director Eric McKenzie told CNN. Approximately 275 passengers and 12 crew members were on board, Amtrak said in its statement.

Speed data on the route, data recorder information and camera footage from Amtrak will be requested by a "Go Team" of 16 investigators when they arrive Tuesday morning, NTSB Chair Jennifer Homendy said Monday.

The NTSB team will include "specialists from mechanical, from signal systems, from operations and survival factors. We'll have a highway person, a drone operator, and some team members from NTSB's Office of Transportation Disaster Assistance to work with survivors and families of those who were involved in the derailment," Homendy said.

Amtrak officials said in a statement Monday night they were "deeply saddened" over the loss of life and injures.