BREAKING: Two explosions at flooded Texas chemical plant where small town was poised as 'extremely flammable' materials increased in heat

Two explosions have been heard near a chemical plant outside of Houston, hours after a spokesman warned a gas explosion was imminent.  

The explosions came after The Arkema Inc plant in Crosby, Texas, lost power and its backup generators amid Harvey's days-long deluge, leaving it without refrigeration for chemicals that become volatile as the temperature rises.

Just after 2am local time, the Harris County Emergency Operations Center reported explosions at the plant and black smoke rising from the facility.

The Harrison County Sheriff's Office said that at least one officer had been taken to the hospital after inhaling fumes following the explosion. 

'One deputy taken to hospital after inhaling fumes from Archem (sic) plant in Crosby,' the HCSO said in a tweet. '9 others drove themselves to hospital as precaution.' 

Arkema said in a statement that more explosions could take place in the coming hours or days and warned residents not to return to the area until it has been cleared.

The plant said in a statement: 'Organic peroxides are extremely flammable and, as agreed with public officials, the best course of action is to let the fire burn itself out.

'We want local residents to be aware that product is stored in multiple locations on the site, and a threat of additional explosion remains. Please do not return to the area within the evacuation zone until local emergency response authorities announce it is safe to do so.' 

The Arkema Inc plant in Crosby, Texas, (pictured) is set to explode, though the timing of the explosion and the extent of the danger weren't immediately clear, according to a spokesperson for the French company

Residents wade through flooded streets in Crosby, Texas, after Hurricane Harvey caused heavy flooding on Wednesday

Emergency vehicles drive on flooded highway 90 after Hurricane Harvey caused heavy flooding in Crosby, Texas on Wednesday

 The plant said that it followed its hurricane preparation plan in advance, but flooding caused the power outage.

'We have been working closely with public officials to manage the implications of this situation, and have communicated with the public the potential for product to explode and cause an intense fire,' the statement said.

The organization said it has been working with local, state and federal officials to manage the situation.

Arkema spokeswoman Janet Smith warned on Wednesday night that an explosion could happen, though the timeline was unclear. 

'The fire will happen. It will resemble a gasoline fire. It will be explosive and intense in nature,' Smith told The Associated Press.

There was 'no way to prevent' the explosion, chief executive Rich Rowe said earlier Wednesday, who added that the plant was in six feet of water and critical refrigeration of the materials had been lost. 

Arkema manufactures organic peroxides, a family of compounds used for making everything from pharmaceuticals to construction materials.

'As the temperature rises, the natural state of these materials will decompose. A white smoke will result, and that will catch fire,' Smith said. 'So the fire is imminent. The question is when.'

The company shut down the Crosby site before Harvey made landfall last week, but a crew of 11 had stayed behind. That group was removed and residents within 1.5 miles were told to evacuate Tuesday after the plant lost power.

Harris County Fire Marshal spokeswoman Rachel Moreno said the 1.5-mile radius was developed in consultation with the US Department of Homeland Security and other subject-matter experts.  

The plant falls along a stretch near Houston that features one of the largest concentrations of refineries, pipelines and chemical plants in the country.

Meanwhile, about 150 miles west of Houston, almost 30,000 gallons of crude oil and about 8,500 gallons of wastewater spilled because floodwaters from Harvey toppled two oil storage tanks, state officials said Wednesday.

Burlington Resources Oil and Gas reported the spills in DeWitt County to the Texas Railroad Commission on Wednesday. They include a 16,170-gallon (385 barrels) spill near the town of Westhoff and a 13,272 gallon (316 barrels) spill west of Hochheim.

It was not immediately clear if any of the spilled oil was recovered. 

There was 'no way to prevent' the explosion at the Arkema chemical plant, chief executive Rich Rowe said earlier Wednesday. Pictured: A car is seen submerged after Hurricane Harvey caused heavy flooding in Crosby on Wednesday

Arkema manufactures organic peroxides, a family of compounds used for making everything from pharmaceuticals to construction materials. Pictured: Residents wading through a street in flooded Crosby, where the chemical plant is set to explode

The company shut down the Crosby site before Harvey made landfall last week, but a crew of 11 had stayed behind. That group was removed and residents within 1.5 miles were told to evacuate Tuesday after the plant lost power. Pictured: Residents wading through the flooded streets of Crosby

Burlington Resources is a subsidiary of ConocoPhillips. Company representatives did not immediately respond to telephone and email messages seeking comment.

More damage to oil industry infrastructure is expected to emerge as floodwaters recede.

Arkema's plant is required to develop and submit a risk management plan to the U.S. Environmental Protection Agency, because it has large amounts of sulfur dioxide, a toxic chemical, and methylpropene, a flammable gas. 

The plans are supposed to detail the effects of a potential release, evaluate worst-case scenarios and explain a company's response.

In its most recently available submission from 2014, Arkema said potentially 1.1million residents could be impacted over a distance of 23miles in a worse case, according to information compiled by a nonprofit group and posted on a website hosted by the Houston Chronicle.

But, Arkema added, it was using 'multiple layers of preventative and mitigation measures' at the plant, including steps to reduce the amount of substances released, and that made the worst case 'very unlikely.'

Daryl Roberts, the company's vice president of manufacturing, technology and regulatory services in the Americas, did not dispute that worst-case scenario but said that assumed all the controls in place failed and strong winds blew directly toward Houston, the nation's fourth-largest city.

'We have not modeled this exact scenario but we are very comfortable with this 1.5-mile radius,' Roberts told the AP. 

He added that it mostly resembled less serious scenarios that would affect a half-mile radius and a few dozen people.

Roberts said the vessels containing the organic peroxide are equipped with controls to slow the release of chemicals. Because of the water, he said, the chemicals will quickly vaporize, reducing the size and scope of the fire.