Homes and businesses in a Houston suburb have been evacuated while a large pipeline fire that started Monday morning continues burning itself out.

A 20-inch pipeline caught fire just before 10 a.m. Monday in La Porte, Texas, which is about 25 miles southeast of Houston, sending a plume of flames into the air and prompting street closures and the evacuation of nearby homes, authorities in La Porte and nearby Deer Park said.

The pipeline carrying liquid natural gas is owned by Energy Transfer and authorities have not determined what caused the fire, Deer Park Mayor Jerry Mouton told reporters Monday.

For hours, dozens of firefighters have poured water into nearby homes and a park that caught fire. Officials said the pipeline had been isolated but as for the fire, Mouton said “it will be a while before it goes down.”

Energy Transfer, in a statement to CNN, said there was an incident at one of its valve stations.

“The line has been isolated so that the residual product in the line can safely burn itself out. We have no timeline at this point on how long that process will take, but we are working closely with local authorities,” the company said.

At least 50 people were evacuated because of the fire but “significantly” more people have been impacted by power outages, evacuations and closures in the area, Deer Park Police Assistant Chief Frank Hart said.

CenterPoint Energy, a Houston-based utility company, showed several outages in the area Monday morning. The company said it was monitoring the incident, which it noted was “unrelated to the company’s natural gas operations or equipment.”

“When it is safe to do so, our electric crews will go into the area to assess the damage to our transmission and distribution power lines, poles and equipment and begin restoring service to impacted customers as safely and quickly as possible,” the company said in a statement to CNN.

One firefighter was treated for minor injuries, Hart said.

Some schools in the area, including the central campus of San Jacinto College, issued a shelter-in-place order because of the fire and later canceled classes and activities.

Geselle Melina Guerra, a 25-year-old who lives in a mobile home within the evacuation area, told The Associated Press she was having breakfast when she heard the explosion.

“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.

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