FRANKLIN, Mass. (AP) – An inbound commuter train plowed into a low-bed truck carrying construction equipment that was stuck at a railroad crossing Monday morning, injuring 19 people, a transit authority spokesman said.

Massachusetts Bay Transportation Authority spokesman Joe Pesaturo said a sign near the Fisher Street crossing in Franklin warned that type of low-bed truck shouldn’t attempt to cross the rails.

“The crossing is at a slight incline. The low-bed truck bottomed out and became stuck on the tracks,” he said.

Injured were 18 passengers and the train’s engineer, who was treated and released from the hospital with a hurt shoulder, Pesaturo said. Many of the passengers also had been treated for minor injuries and released by Monday afternoon.

“The people came off. They were very calm,” witness Pete Arbogast said. “They kind of took care of each other, made sure everyone was all right. Everyone was on a cell phone, calling somebody. It wasn’t as chaotic as you would think it would be.”

The construction equipment with a bucket attached was on the low, flatbed truck. The truck driver had left his vehicle and was walking up the tracks in an effort to warn the oncoming train bound for Boston, Pesaturo said.

The train engineer saw the truck driver waving, but was unable to stop in time. When the train engine struck the truck shortly before 8 a.m., the construction equipment swung around and slammed into the first coach of the train.

When the engineer realized he couldn’t stop, Pesaturo said he told passengers in the front car to brace for an impact.

“It may have played a role in why no one was seriously injured in this accident,” he said.

Transit police and the National Transportation Safety Board were investigating.

Passengers were bused between two stations to avoid the scene, but Pesaturo said normal service resumed by Monday’s afternoon commute.