Two adults, including a pregnant woman, and two children are dead after an 18-wheeler caught fire near Interstate 20 and Interstate 35E Monday morning, authorities say.
As responders were able to move closer to the 18-wheeler, police said they found another vehicle wedged underneath. The second vehicle was destroyed in the fire.
Two adults, two children and one unborn child were found dead, according to Dallas County Sheriff's spokesman Raul Reyna.
The driver of the 18-wheeler, operated by Southeastern AG Transport Inc., of Mississippi, was not injured, Reyna said.
Investigators said the 18-wheeler and the other vehicle somehow became entangled, rupturing the 18-wheeler's gas tanks and causing the fire.
Authorities closed the westbound ramp from I-20 to I-35E while they battled the fire. The ramp reopened at about 3:30 p.m., after Texas Department of Transportation engineers inspected the bridge.
"The inspection is complete and there's no structural damage to the bridge," TxDOT spokesman Ryan LaFontaine said.
The 18-wheeler was transporting a load of lumber, much of which spilled off the trailer and onto the ground below the overpass.
The Dallas County medical examiner said it could be the end of the week before officials release the names of the people who died in the collision.
NBC 5's Jeff Smith and Holley Ford contributed to this report.