The roof of one of the coal units caught fire at the NRG WA Parish power plant at 2500 Yu Jones Road near Smithers Lake around 11:40 p.m. Sunday.

Officials said it was a fight to keep the flames from spreading.

Fortunately, there were no injuries and the fire is mostly extinguished, according to an NRG spokesperson. They said everything is safe and there is no danger to the community or the environment.

The plant is still operational, but some firefighters will remain on site Monday to ensure there are no hot spots.

Damage is easy to spot at the WA Parish Power Plant. Flames leaped into the air as the factory caught fire overnight. You can see the SkyEye video of the damage in the video player above.

“Our operators called the fire department. We had a terrific response from the fire department,” said David Knox, a spokesman for NRG.

In total, more than 100 firefighters from 20 departments and two different departments responded around midnight.

“Each of them worked together to control it to make sure it didn’t spread,” Fort Bend County Fire Marshal Mark Flathouse said.

The unit that caught fire – which houses mostly machinery – immediately shut down, which officials say it is designed to do.

In addition to the absence of employee injuries, NRG said there were no environmental concerns.

The plant provides approximately 15% of the energy for Houston and surrounding areas.

The damaged unit stays off, affecting the power supply.

“This unit on a hot day, when all the air conditioners are running, it meets the needs of about 12,000 homes,” Knox said.

ABC13 contacted ERCOT for more details on the impact this could have on customers, and sent the following statement:

“ERCOT continues to plan for sufficient electricity supply to meet demand as exceptionally high temperatures remain in place across much of Texas. ERCOT will continue to deploy all available tools to reliably manage the grid and coordinate closely with the Public Utility Commission, generation resource owners and transmission utilities to ensure they are also prepared.”

As for when crews can assess the damage, they will need to deem the area safe before they can enter and investigate.

The cause of the fire was not immediately known.

To learn more about this story, follow Charly Edsitty on Facebook, Twitter and Instagram.