LA PORTE, Texas (AP) — A massive pipeline fire shooting a towering pillar of flame for hours over suburban Houston on Monday as first responders evacuated a surrounding neighborhood and tried to keep more nearby homes from catching fire.

The blaze involving a 20-inch pipeline carrying natural gas liquids must burn itself out, according to its operator, Dallas-based Energy Transfer. The company said the gas flow was shut off but residual material inside could burn for hours to come.

Firefighters were dispatched at 9:55 a.m. after an explosion that rattled adjacent homes and businesses in Deer Park and La Porte, about 25 miles (40 kilometers) southeast of downtown Houston, long the energy capital of the U.S. The plume of smoke could been seen from at least 10 miles away, and nearby there was a chemical smell in the air. There was no immediate word on whether anyone has been injured.

Geselle Melina Guerra said she and her boyfriend heard an explosion at around 9:30 a.m. as they were having breakfast in their mobile home. “All of a sudden we hear this loud bang and then I see something bright, like orange, coming from our back door that’s outside,” said Guerra, 25, who lives within the evacuation area.

Her boyfriend woke up his brother and they ran to their car.

“I was just freaking out, pacing around the living room, not really knowing what to do or what was happening,” Guerra said. “I thought maybe it was an airplane that had crashed down by our house.”

La Porte city spokesperson Lee Woodward told KTRK-TV that people in nearby schools were told to shelter in place as law enforcement blocked off a wide area.

At nearby San Jacinto College, which closed its campus after the explosion, people who gathered included Evan Wyman, who had gotten word after calling police that her dog Baxter had been rescued from her home, which is in the evacuated neighborhood.

“I just know that my dog is rescued,” Wyman said.

At least one gas transmission pipeline and one hazardous liquid pipeline run through the area on fire, according to U.S. Department of Transportation geographic data from the Pipeline and Hazardous Materials Safety Administration. Another gas transmission pipeline cuts diagonally through a nearby residential neighborhood along Spencer Highway, which runs through the suburbs of Deer Park and La Porte.

The cause of the fire was not immediately known. Houston is the nation’s petrochemical heartland and is home to a cluster of refineries, plants and thousands of miles of pipelines. Explosions and fires are a familiar sight to residents in Texas’ largest city, including some that have been deadly. The blasts have raised recurring questions about the adequacy of the industry’s plans to protect the public and the impacts of environmental damage.

Video images from KTRK showed a park near the fire had been damaged and firefighters pouring water on adjacent homes. By noon, at least a couple of homes appeared to have caught fire, with smoke pouring from their roofs. There are also several businesses nearby, including a Walmart.

Sanchez said they’re used to evacuations because they live close to other plants near the highway. But in the 10 years Sanchez has lived there, he had not witnessed an explosion.

“We just drove as far as we could because we didn’t know what was happening,” Sanchez said from a parked car at a gas station near his college.

Officials have ordered residents in the Brookglen neighborhood area near the fire to evacuate, Woodward said in an email.

“Please avoid the area and follow law enforcement direction. Further details will be released as available,” Woodward said.

There are several high-voltage power lines near the fire. The website PowerOutage.us said several thousand customers were without power in Harris County.

CenterPoint Energy said it is monitoring the fire, which is near Spencer Highway in LaPorte. The company said the fire “is unrelated to the company’s natural gas operations or equipment.”

The company said that when it’s safe, their crews will assess the damage to their transmission and distribution power lines, poles and equipment and will start restoring power to impacted customers.