PORT NECHES, Texas — Two massive explosions 13 hours apart tore through a Texas chemical plant Wednesday, and one left three workers injured.

The blasts blew out windows and doors of nearby homes and prompted a mandatory evacuation of a 4-mile (7-kilometer) radius from the plant in Port Neches in Southeast Texas, about 80 miles (129 kilometers) east of Houston. Officials say they have no estimate for how long the fire will burn.

The initial explosion at the TPC Group plant, which makes chemical and petroleum-based products, occurred around 1 a.m. It sent a large plume of smoke stretching for miles and started a fire.

The three workers hurt during the blast —two TPC employees and a contractor — were treated at hospitals and released, said Troy Monk, TPC’s director of health, safety and security. About 30 employees working at the plant at the time of the explosion were all accounted for, according to TPC.

Jefferson County Judge Jeff Branick, the top county official, told Beaumont TV station KFDM that it’s a miracle no one died. He said one worker suffered burns and the others had a broken wrist and a broken leg.

Monk said the blast occurred in an area of the plant that makes butadiene, a chemical used to make synthetic rubber and other products. He said the plant has 175 full-time employees and 50 contract workers.

The second blast ripped through the plant about 2 p.m., sending a steel reactor tower rocketing high into the air. That prompted Jefferson County Judge Jeff Branick, the top county official, to order a mandatory evacuation of Port Neches and neighboring Groves, Nederland and part of Port Arthur. Water cannons were trained on surrounding plant works and tanks to keep them cool and avoid further explosions.

At a Wednesday night news conference, Branick said a loss of power at the plant prevented any investigation into the cause of the explosions or how much damage was done to the facility. Likewise, he said there was no estimate yet for the amount of damage to the surrounding neighborhoods.

Smoke and fire are visible from the TPC Group Port Neches Operations explosion on Wednesday, Nov. 27, 2019, in Port Neches, Texas. Three workers were injured early Wednesday in a massive explosion at the Texas chemical plant that also blew out the windows and doors of nearby homes. (Marie D. De Jesus /Houston Chronicle via AP)

Monk said TPC would form an investigation team to determine what led to the explosions.

“We’re staying focused on the safety of our emergency response personnel folks in and around in the community as well as trying to protect the environment,” Monk said at a news conference.

Firefighters have not been able to fully assess the damage at the plant, he said.

Branick, who lives near the plant, said at the news conference that he was awakened at his home by the initial blast, which blew in his front and back doors, “damaging them pretty significantly.”

Jefferson County Emergency Management coordinator Mike White told the Beaumont Enterprise that five residents were being treated for minor injuries, mostly related to shattered glass. He said state environmental officials were monitoring air quality but that no elevated chemical levels had been detected.

Texas has seen multiple petrochemical industry blazes this year, including a March fire that burned for days near Houston and another that killed a worker at a plant in nearby Crosby.

In the March fire, prosecutors filed five water pollution charges against the company that owns the petrochemical storage facility after chemicals flowed into a nearby waterway.