No injuries were reported, but roads were closed and houses were ordered evacuated within a mile of the Duke Energy site, about 40 miles northeast of Houston.
Witnesses said in broadcast reports that they saw a ball of fire from a bridge over the Trinity River.
One person who was inside the storage site when the gas exploded managed to escape, said Capt. Bill Tidwell of the Liberty County Sheriff's Department.
``Everybody's been accounted for,'' he said.
Crews decided to let the gas burn itself out, and two other storage chambers at the facility were not thought to be threatened, he said. Emergency crews remained on the scene well past daybreak.
The cause of the explosion was not immediately known.
Danny Gibbs, a spokesman for Charlotte, N.C.-based Duke Energy, said there were no environmental or safety concerns. ``Natural gas is burning, but it will dissipate,'' Gibbs said.
Gibbs said he did not know how long the gas would burn.
The sparsely populated area is dotted with manmade caverns inside salt domes, the world's largest storage site for explosive hydrocarbons. In 1980, an underground gas leak in nearby Mont Belvieu forced 72 families from their homes for almost five months.
