On Monday, a liquefied natural gas pipeline burst near Houston, prompting authorities to evacuate homes and businesses while several schools were placed under curfew.

In Deer Park, where the fire started and is about 20 miles southeast of Houston, about 50 homes were covered by evacuation orders. At least some of the five apartment buildings near the fire’s source were damaged, city officials said at a news conference.

A firefighter from nearby Pasadena was injured near the fire, officials from the neighboring city of La Porte said in a statement. Details on the extent of the injury or the firefighter’s condition were not available, and Pasadena fire officials did not immediately respond to a request for more information Monday.

Nearly 1,000 homes and businesses in La Porte were affected by evacuation orders, according to a statement from the city. In addition, the La Porte Independent School District said curfews have been imposed on several of the district’s campuses.

The orders affect “all homes and businesses within a half-mile radius of the accident site,” said a statement from Energy Transfer, the operator of the burning pipeline.

A vehicle may have struck the pipeline infrastructure before the flames broke out, the company said, adding that the cause of the fire and the possible rupture were still being investigated.

Classes at San Jacinto College’s central campus in Pasadena have been canceled and students remaining there have been told to stay home until authorities give the all-clear, the college said on Facebook.

Deer Park said in its own statement that a Walmart store and a HEB grocery store were also affected by curfews.

Deer Park city officials said at the news conference that some residents and businesses could also be affected by power outages because power lines may have been damaged; the region’s power company reported a single-digit number of locations without power.

The pipeline fire broke out at Energy Transfer’s facility – the company says it is its La Porte location, but both cities say it is in neighboring Deer Park – just before 10 a.m., Deer Park and La Porte statements said.

According to a statement from the Deer Park Emergency Management Office, Deer Park and La Porte fire departments have established a joint command to fight the blaze from the west and east, respectively. Energy Transfer has shut down the affected pipeline while firefighters wait for the last of the fuel to burn, Deer Park officials said.

“All I can say is it will take a few hours for the product to burn off,” said Jerry Mouton Jr., mayor of Deer Park.

Several houses were damaged, he said, and a grass fire that broke out nearby had been contained.

“The fire is very hot,” said Mouton. “Many of the neighboring houses are still burning, although we are pouring a lot of water on them to get the fire under control.”

The fire broke out at a valve station for a 20-inch Y-line for liquefied natural gas, Energy Transfer said in a statement.

“The line has been isolated so that the residual product in the line can burn out safely,” the company said. “We currently have no timeline for how long this process will take.”

Air monitoring by Harris County Pollution Control found no measurable volatile organic compounds and a “moderate” amount of particulate matter, it said in a statement. People with respiratory or other health problems “should take precautions,” it said.

The city of Deer Park said Energy Transfer has set up a hotline for residents, businesses and others affected by the fire: 855-430-4491. Emergency crews may be available, the city said.

Several reunification sites were provided for evacuees in Deer Park and La Porte, including an activity center and a church.