The deaths of five oil field workers Thursday in a fiery four-vehicle crash is the latest accident linked to increased traffic from the Eagle Ford Shale drilling and fracking boom that has caused dangerous roads in South Texas.

According to Texas Department of Public Safety Trooper Maria Loredo, the crash happened around 7 a.m. Thursday on U.S. 83 in Dimmit County, about 115 miles south of San Antonio.

A tanker truck loaded with oil rolled onto its side after it hit a pickup that had slowed down on U.S. 83 near Asherton, according to reports. A van carrying five men and another vehicle hit the truck’s tank, and both vehicles burst into flames.

DPS identified the dead as Justin Lara, 21; Juan Francisco Medellin, 65; Edward Pena, 22; Carlos Rubio, 30; and Sergio Javier Veyro, 50, said Raul Leal, public information officer for the Texas Department of Transportation’s office in Laredo.

All of the men, from Laredo, were heading home when they were killed, Loredo said.

The man driving the pickup was taken to a San Antonio hospital with burns to 80 percent of his body.

According to data compiled by the Houston Chronicle, triple tragedies — crashes that kill three or more people — are common in the Eagle Ford Shale area. The death toll has increased from 72 in 2010 to 101 in 2012 and 148 in 2013.

Leal said in his Laredo district the increased traffic is noticeable and that TxDOT has tried improvements to increase safety in heavy traffic areas such as U.S. 277 and U.S. 83, in Carrizo Springs and Eagle Pass.

“We know there is a lot more traffic now because of the Eagle Ford Shale energy sector within our district, especially on U.S. 83 in north Webb and Dimmit counties,” he said.

Leal said TxDOT has added short-term passing lanes on U.S. 83 and some on U.S. 277. Known as a “Super 2” design, they provide an extra lane for motorists to safely pass slower vehicles.

“We’ve tried to do things to alleviate the traffic,” Leal said. “We can’t do four lanes, but we can come up with Super 2s for safety, which is our No. 1 priority.”

Isaac Garcia, an oil field worker, told the Associated Press he was delivering pipe when he came across Thursday’s crash.

“There were just flames all over the place,” he said. “It took seconds for it to light up the way it did.”

Garcia said it was the second crash he has seen in that spot.

“You’ve got to be real cautious on that road,” he said. “With wet conditions and oil mixed with mud (coming off 18-wheelers), it’s just meant for accidents to happen.”

Staff Writer Mark D. Wilson and the Associated Press contributed to this report.