The train, en route from Los Angeles to Chicago, had 243 passengers on board.
MENDON, Mo. -- Four people are dead and approximately 150 are injured after an Amtrak train derailed after hitting a dump truck that was in an uncontrolled public crossing in Mendon, Missouri, according to Amtrak and officials.
Eight passenger cars and two locomotives derailed at about 12:42 p.m. local time, Amtrak said.
Authorities confirmed Tuesday that a third passenger was killed, along with someone who was in the dump truck.
The Missouri State Highway Patrol tweeted Tuesday that approximately 150 people were injured.
"It was something that you never think is going to happen, but when it does happen, it's far worse than anything you could have imagined," Jason Drinkard, a passenger on the train, told ABC affiliate station KMBC in Kansas City, Missouri.
Drinkard, a high school teacher, said he was traveling with his wife and six students to Chicago for a conference, when the crash occurred. He described seeing the "carnage," with injured passengers and crew unable to walk.
The train was en route from Los Angeles to Chicago with 243 passengers and 12 crew members on board at the time of the crash, Amtrak said. All the train occupants from the scene were evacuated, according to Dunn.
Dozens of people have been hospitalized. Officials at Hendrick Medical Center accepted seven patients from the scene, while officials at MU Health Care University Hospital/Columbia said its facility was treating 16 patients as of 10 p.m. ET. Pershing Memorial Hospital received between 15 and 20 people from the accident.
Passenger Rob Nightingale, 58, told ABC News his train car tipped to the side and he climbed through a window to escape. He said he saw a little girl crying and her family trying to comfort her.
Some people were covered in blood, he added.
Aboard the train were two Boy Scout troops from Appleton, Wisconsin, that sprang into action, breaking windows and helping to evacuate passengers, two of the scouts' mothers told ABC affiliate station WBAY in Green Bay, Wisconsin. The scouts even attempted to save the life of the dump truck driver, the mothers, Sarah Berken and Nicole Tierney, said.
MORE: Boy Scouts jump into action after Amtrak train derailment
Berken and Tierney said they both described a nerve-racking period of time between learning of the crash and hearing that their sons survived the crash without injuries.
"Until I heard from my son an hour later, that he was OK, I couldn't stop shaking or crying," Berken said.
Tierney added, "It was a phone call that no parent should ever have to receive. It was probably way up there on the scariest moments of my life."
Scott Armstrong, a spokesman for the Boy Scouts of America, told WBAY there were 16 scouts, ages 13 to 17, and eight adult chaperones who were returning home from a week-long backpacking trip at a wilderness camp in New Mexico. He said two of the adult chaperones were injured, one suffering broken ribs and a bruised lung and the other suffering a cracked vertebrae.
Missouri Public Safety officials, highway patrol troopers and other personnel were dispatched to the scene, Missouri Gov. Mike Parson tweeted.
The National Transportation Safety Board said it launched a 14-member go-team to investigate the crash. The team is scheduled to arrive Tuesday.
Mendon is about 100 miles northeast of Kansas City, Missouri.
This comes one day after an Amtrak train collided with a car in California, killing three people.
U.S. Transportation Secretary Pete Buttigieg said in a statement, "My thoughts are with the victims and families affected by today's Missouri train derailment and the Northern California collision that occurred over the weekend. I have been updated on these crashes and my team is in communication with Amtrak and the relevant authorities."
FRA personnel are en route to Mendon, where they will support NTSB investigators, he added.
ABC News' Sam Sweeney contributed to this report.
By The Associated Press