MENDON, Mo. (NewsNation) —A fourth person has died from injuries suffered in an Amtrak train derailment in Missouri in which about 150 people suffered minor to serious injuries, the state Highway Patrol said Tuesday.

The train was traveling from Los Angeles to Chicago Monday afternoon when it struck a dump truck in north central Missouri, causing at least seven rail cars to tumble off the tracks and land on their sides.

Amtrak’s Southwest Chief was carrying about 275 passengers and 12 crew members when the collision occurred near Mendon at a rural intersection on a gravel road with no lights or electronic controls, according to the Highway Patrol. The Southwest Chief takes about two days to travel from Los Angeles to Chicago, picking up passengers at stops in between. Mendon, with a population of approximately 160, is about 84 miles northeast of Kansas City.

Two of those killed were on the train and the third person killed was in the truck, Missouri State Highway Patrol spokesman Cpl. Justin Dunn said. The identity of the fourth person who died was not released, but police said they had also been on the Southwest Chief train.

Passenger Diane Couture and her husband were on a 40th wedding anniversary trip to the Grand Canyon.

“We were on the right-hand side. The people on the left flew across and the windows on our side became the floor,” Couture told NewsNation affiliate WDAF. “There were two gentlemen that stepped up and stacked the cushions and these crates on top of each other. They knocked the window out and pulled us up to the top of the train.”

Rob Nightingale said he was dozing off in his sleeper compartment when the lights flickered and the train rocked back and forth.

“It was like slow motion. Then all of a sudden I felt it tip my way. I saw the ground coming toward my window, and all the debris and dust,” Nightingale told The Associated Press. “Then it sat on its side and it was complete silence. I sat there and didn’t hear anything. Then I heard a little girl next door crying.”

The collision broke the dump truck apart, he said.

Passengers included 16 kids and eight adults from two Boy Scout troops who were traveling home to Appleton, Wisconsin, after a backcountry excursion at the Philmont Scout Ranch in New Mexico. No one in the group was seriously injured, said Scott Armstrong, director of national media relations for the Boy Scouts of America. The Scouts administered first aid to several injured passengers, including the driver of the dump truck, Armstrong said.

18 patients were treated, including eight who were released, from MU Health Care as of Tuesday afternoon, reports say.

Local farmer Mike Spencer said he had complained about the intersection to local authorities, describing it as deadly.

“Our hearts really go out to the families. You know, I tried to prevent this, I’ve done everything I knew to do in my power,” Spencer said. “I’ve talked to numerous people. And anyway, I’m just really saddened that I wasn’t able to do more.”

National Transportation Safety Board Chairwoman Jennifer Homendy said It’s too early to speculate on why the truck was on the tracks but that a team of NTSB investigators was expected to arrived Tuesday evening to begin the process of obtaining more answers.

While at the news conference, Homendy said the federal agency has recommended lights and bells at crossings since the 1990s and that the “passive crossing” where the crash occurred did not have active lights or bells to warn drivers of oncoming trains.

The probe into the crash will involve investigators downloading the event recorder to obtain information on exactly when the engineer blew the horn, how fast the locomotive was going, when the breaks were applied, footage from two forward-facing cameras, studying data from the truck and signal system, as well as interviewing the train crew.

Amtrak is a federally supported company that operates more than 300 passenger trains daily in nearly every contiguous U.S. state and parts of Canada.

It was the second Amtrak collision in as many days. Three people in a car were killed Sunday afternoon when an Amtrak commuter train smashed into it in Northern California, authorities said.

U.S. Transportation Secretary Pete Buttigieg tweeted a statement Monday evening:

“Saddened by the tragic loss of life and injuries in the Missouri train derailment today & Northern California collision over the weekend. I have been kept updated & my team is in touch with Amtrak & relevant authorities. FRA staff are en route to support the investigation in MO.”

The Associated Press and NewsNation affiliate WDAF contributed to this report.