FORT WORTH (CBSDFW.COM) – Trinity Railway Express (TRE) trains are back operating on a regular schedule — two days after a deadly crash involving a dump truck.

At 5:30 a.m. Monday there were no passengers onboard the TRE, but at the time of the crash on Saturday there were more than 30 people on the train.

The crash happened around noon on Calloway Cemetery Road, right at the border of Fort Worth and Arlington.

Railroad crossing lights begin to flash about 47 seconds before a train enters a crossing. A transit spokesperson says it appears the driver of the dump truck ignored those lights and went around the crossing arm.

Emergency calls released Monday support that theory. One caller told an operator with MedStar Emergency Medical Services, “We’re coming up to where the train crosses the street and the sign was down and the truck tried to make it across the track and the train smashed into the truck and it blew up.”

The exact reason why the truck stopped on the train tracks may never fully be known since both the driver and passenger — Arnell Tolliver and Charlene Alexander — were killed in the crash.

Several people onboard the TRE were hurt, including two with critical injuries.

Passengers said there was a lot of chaos and confusion after the crash. “It was a pretty scary event. I was a bit shaken at first. I’m calm now,” rider Santos Vargas said as he waited with other uninjured passengers underneath on overpass. It’s my first time riding the train down to Fort Worth. I was going on a little adventure. So, this is not the kind of excitement I was looking for.”

CBS 11 News spoke with crisis response expert Ken Jenkins about what typically happens next in an investigation like this.

“What we also know from looking at the impact and the debris field, that even as they [TRE train] slowed down, the speed was significant enough not only to completely destroy the truck, but also to blow the windows out on the train,” he said.

According to officials, TRE trains are authorized to go 79 miles per hour. On Monday officials with Dallas Area Rapid Transit (DART) confirm the train was traveling 74 miles per hour at the time of impact.

The TRE train had a two-person crew onboard; an engineer and conductor. The conductor was one of those transported to a local hospital for treatment. He was released on Sunday. The engineer was checked out by medical staff at the accident scene and allowed to go home.

This morning many riders said they are aware of what happened over the weekend but aren’t discouraged from taking the train.

Officials with the Federal Railroad Administration confirm they are assisting with the crash investigation.