DEER PARK, Texas (AP) — Human remains were found inside an SUV that authorities say hit an aboveground valve on a pipeline in suburban Houston, causing a fire that has burned for four days, officials said Thursday.

With the fire substantially smaller since it began on Monday, police were able to access the area around the pipeline in Deer Park. Investigators removed the white SUV and towed it away Thursday morning.

While medical examiners with Harris County were processing the vehicle, they recovered and removed human remains found inside, Deer Park officials said in a statement.

“They will now begin working through their identification process, which will take some time,” officials said.

Authorities have offered few details on what caused the vehicle to hit the pipeline valve. Energy Transfer, the Dallas-based company that owns the pipeline, on Wednesday called it an accident. Deer Park officials said preliminary investigations by police and FBI agents found no evidence of a terrorist attack.

The pipeline is a 20-inch-wide (50-centimeter-wide) conduit that runs for miles through the Houston area. It carries natural gas liquids through Deer Park and La Porte, both of which are southeast of Houston. Officials say they expect the fire to be extinguished sometime Thursday evening.

Authorities evacuated nearly 1,000 homes at one point and ordered people in nearby schools to shelter in place. Officials began letting residents return to their homes on Wednesday evening.

Juan A. Lozano, The Associated Press