(CNN) -- A natural gas pipeline exploded Tuesday in the Texas Panhandle, killing two construction workers and injuring three others, an official said.
The Lipscomb County Sheriff's Office was alerted to the explosion at 4:08 p.m. (5:08 p.m. ET) three miles northeast of Darrouzett, said Sheriff James Robertson in a news release.
Fire trucks from a number of nearby counties, including from across the state line in Oklahoma, responded, he said.
The five people were working for a dirt contracting company hauling caliche, a hardened deposit of calcium carbonate used as a road base and surface material, when a bulldozer struck the pipeline, he said.
In addition to the fatalities, two people escaped with non-life-threatening injuries, and a fifth person was taken by helicopter to a hospital in Oklahoma City with unknown injuries, Robertson said.
Darrouzett is an oil, gas and ranching town of about 300 residents in the Panhandle. "It's very rural," said sheriff's spokeswoman Vickie Nelson.
By 7 p.m. (8 p.m. ET), video of the site showed a blackened patch of grassland hundreds of feet in diameter. In the center of the patch stretched a white strip of ground that contained the smoldering carcasses of three 18-wheel trucks, a van, a flatbed truck and two tractors.
Tuesday's explosion came a day after a 36-inch underground natural gas pipeline in Johnson County, Texas, 300 miles south-southeast of Darrouzett, burst into flames as construction work was being carried out nearby. One person died, and a number of others were hurt.