HANFORD, Calif. — At least 40 people were hurt Monday afternoon when a big rig and an Amtrak passenger train collided south of Hanford in central California.

The collision happened about 12:20 p.m. on the BNSF Railway freight tracks at Kansas Avenue. The impact partially derailed the passenger train, which shares tracks with freight trains on the line between Bakersfield and Hanford. The train came to a halt more than a quarter mile south of the crossing.

Dan Lynch, director of Kings County Emergency Medical Services, said the truck driver was pinned in his vehicle for about an hour following the crash. Investigators did not immediately know the driver’s name or age or the extent of his injuries, but California Highway Patrol information officer Jerry Pierce said he reportedly received moderate injuries.

Pierce said investigators had not yet determined if the truck crossed the tracks into the train’s path, or if the truck struck the train broadside. But witnesses told investigators that the automated gates at the crossing were down, signaling traffic to stop for the train. The truck was hauling a load of cotton trash — the stuff left over after the ginning process. The impact left the cab of the truck demolished and the rig overturned on the tracks. Some small pieces of debris from the truck were visible hundreds of yards south of the crossing.

Amtrak spokeswoman Vernae Graham said the southbound train carried 169 passengers. The train had left Hanford’s Amtrak station just a few minutes before the crash, which partially dislodged two of the four double-deck passenger cars and a locomotive that was bringing up the rear.

The Rev. Catherine Wagar was riding in the upper level of a rail car on her way home to Los Angeles when “it felt like something big had slammed the west side of the car, just below the one I was riding in. Then I felt the train begin to move to the side.”

Wagar said to herself, “ ‘Oh no,’ and I grabbed the table until the train stopped.”

Passengers were evacuated from the train onto an adjacent alfalfa field, where paramedics tended to the injured before they were taken to local hospitals, said Pierce. Most of the passengers who were not hurt were taken by school buses to the Hanford Civic Auditorium to await pickup by their families or to board Amtrak buses to continue their journey south.

All the injuries were either minor or complaints of pain, said Dan Lynch, Kings County Emergency Medical Services director. Patients were taken to six area hospitals. Seven more patients sought treatment after they arrived at the Hanford Civic Auditorium.

At the Hanford Civic Auditorium, Amtrak passengers talked about their experience as they waited for buses to carry them to their destinations.

Passenger Mary Lopez was returning to her home in Hemet in Southern California after visiting her daughter and granddaughter in Fresno when the crash happened. Lopez was in the lower level of the two-tier car when she saw a big cloud of dust and heard something scraping the side of the train.

The rail car began leaning, she said, “and then I thought, ‘Oh … what’s happening?’ I don’t normally cuss, but I was scared.”

Wagar, deacon at the Episcopal Church of St. Philip the Evangelist in Los Angeles, said a young girl sitting in front of her was crying hysterically. Wagar said she did her best to try to calm the girl down.