A fifth man escaped harm and summoned help, Mobile Fire-Rescue spokesman Steve Huffman said.
Mobile police said the men were believed to be transients in their 20s and had been sleeping in an open car, two on top of the beams and three below at the CSX rail yard.
The beams weigh at least several hundred pounds each, and it was unclear how many were stacked in the car.
"It's pretty heavy stuff," Huffman said, adding that the car was being readied to move when the load of beams apparently shifted and fell.
The injured man was taken to the University of South Alabama Medical Center. Police spokesman Christopher Levy said his foot or lower leg was crushed, but that otherwise, "he's going to be fine."
Workers were using a crane to move the beams so the other men's bodies could be recovered, something that was expected to take several hours, Levy said.
The car was en route from Virginia to Houston, CSX spokeswoman Carla Groleau said.
Transients often use rail cars for shelter and transportation and many live temporarily at encampments near the rail yard, Huffman said.
Judith Adams, spokeswoman for the Alabama State Port Authority, which owns property adjacent to the rail yard, said the incident highlighted the dangers of venturing near rail yards when one is unfamiliar with the equipment.
"They were at the wrong place at the wrong time," she said. "It is very, very sad." (Reuters)
