The first explosion rocked the small city of Port Neches on Wednesday morning, injuring three employees. Windows shattered and roofs collapsed in the shock, as more explosions followed throughout the day.

Jefferson County Judge Jeff Branick issued a mandatory evacuation for areas within a four-mile radius of the plant, after one explosion launched a tower into the air “like a missile”.

Residents have been left fearing for their safety following the explosion, as a thick black smoke cloud has descended over the TPC Group plant.

Dramatic videos posted to social media show as flames rise from the plant, the sky illuminated with brilliant shades of orange.

Officials urged people to “shelter in place” as a fire is still raging.

Texas explosion latest: The plant is still on fire 24 hours later (Image: REUTERS)
Texas explosion latest: The explosions sparked a huge fire (Image: REUTERS)
Texas explosion latest: The explosions sparked a huge fire (Image: REUTERS)

Why is the Port Neches fire so dangerous?

The fire at the plant, which makes products for chemical and petroleum companies, fuelled by a chemical called butadiene.

Butadiene – a colourless gas with a gasoline-like smell – is made from processing petroleum and is used to make synthetic rubber and plastics.

Jefferson County Sheriff’s Office Capt. Crystal Holmes said: “Right now, it’s contained and not going anywhere but it’s not under control.”

Health effects from butadiene exposure can vary, according to the Occupational Safety and Health Administration says.

Texas explosion latest:
Texas explosion latest: The fire is being fuelled by a chemical called butadiene (Image: REUTERS)

Lower exposures can cause irritation to the eyes, throat nose and lungs as well as cause frostbite while higher exposures can damage the central nervous system.

Other symptoms include distorted blurred vision, vertigo, general tiredness, lowered blood pressure, headaches or nausea.

The OSHA said: “Several human epidemiological studies have shown an increase in cardiovascular diseases and cancer.

“However, due to the small numbers of cancers and confounding factors such as smoking, and simultaneous exposure to benzene and styrene, a true causal relationship cannot be established.”

The chemical levels in the air tracked about 4 miles away from the explosion are “well below concentrations of health concern or odorous levels,” the Texas Commission on Environmental Quality said.

Texas explosion latest: Port Neches map
Texas explosion latest: The plant was in Port Neches (Image: GOOGLE)

Texas explosion – latest Port Neches evacuations

Nederland Volunteer Fire Department -confirmed an evacuation order was in place – with potentially 50,000 people affected under the mandatory evacuation.

In a post on Facebook, the service said: “Please be aware that there is a mandatory evacuation for everyone within a 1/2 mile of the TPC plant in Port Neches.

“This could change and expand to a greater area, so please pay attention to your local news station as this situation develops since we may not be able to keep this page updated this morning.

“Please tune in to the local news stations for specific shelter in place or evacuation information.”

Texas explosion latest:
Texas explosion latest: Officials urged people to “shelter in place” (Image: REUTERS) 

The explosions came a day before Thanksgiving, on November 28.

Branick said he was sorry for “any plans that might have been interrupted”, adding: “I know that it’s extremely frustrating, particularly on the eve of Thanksgiving, for you to be away from your homes and family, and I can feel your frustration.

“But I want to emphasise that the safety of the community is always going to be our top concern.”

He confirmed everyone has been evacuated from the site and accounted for, but urged people to “shelter in place” as the fire burned.

Search-and-rescue teams will be going from door-to-door to check on the welfare of local residents until the emergency is over.

Where is the TPC Group power plant?

TPC Group said in a statement the initial explosion took place at about 1am on Wednesday at the Port Neches facility, which is about 100 miles west of Houston.

TPC said: “The event is ongoing, but will be brought under control as quickly and safely as possible.

“Right now our focus is on protecting the safety of responders and the public, and minimizing any impact to the environment.”

TPC employs 175 people, with 50 workers on site.