The wreck occurred Monday afternoon on a U.S. 65 bridge in Clinton in north-central Arkansas, about 70 miles north of Little Rock.
"They were like sitting ducks on the bridge," Van Buren County Sheriff Scott Bradley told the Arkansas Democrat-Gazette. "There was nowhere for them to run to get away from the logs."
The driver of the logging truck, Jerry Hickman, 39, of Bee Branch, suffered minor injuries, and 19 people were taken to a hospital in Clinton, officials said. Ozark Health Medical Center administrator David Deaton told the Democrat-Gazette that 12 of those patients suffered "major injuries."
State police on Tuesday identified the two people who died as Ricardo Trochez, 40, of Atkins, and Hubert Keith Moore, 51, of Chester.
It could take a month or longer before the investigation is complete, state police spokesman Bill Sadler told The Associated Press. A preliminary state police report said a rear tire on the big rig's trailer blew out, causing the load to shift and the logs to scatter among the workers.
The crew was working on an Arkansas State Highway and Transportation Department project to widen the bridge from three lanes to five.
Rescue teams had to cross steel rebar rods to reach the injured, Sheriff Bradley told the Democrat-Gazette.
"It was pretty horrific," he said. "We had people trapped under logs, people with broken legs, people with severe head lacerations. It was very chaotic."
The sound of the crash startled Bob Galbreath, who owns a nearby nursery.
"It was violent enough to shake the frame of the greenhouses," he told the newspaper. "It sounded like a natural-gas explosion. That's what I thought at first. I thought one of the construction workers hit a gas line."