(CNN) -- Officials in Texas now say a chemical release happened at a Texas plant overnight, and not explosions.
The releases caused plumes of black smoke Thursday at a flooded chemical plant in Crosby, Texas, near Houston, officials said.
One deputy was hospitalized after he inhaled fumes from the Arkema peroxide plant, the Harris County Sheriff's Office said via Twitter. Nine others drove themselves to the hospital as a precaution, the sheriff's office said.
The incident was reported around 2 a.m. (3 a.m. ET).
The facility, which is between Houston and Beaumont, had been closely monitored after plant officials said they expected a chemical reaction that will likely cause a fire that will "resemble a large gasoline fire."
The thick black smoke "might be irritating to the eyes, skin and lungs," Arkema officials said in a statement.
The scope of the incident is still unknown.
The company shut down the facility as Harvey approached last week and evacuated employees as well as residents within 1.5 miles of plant as a precaution after it was flooded under more than 5 feet of water.
After sitting without power and refrigeration for days, the chemicals at the facility heated up and eventually burned, causing the explosions. It was a matter of time before a fire started, the company had said.
The company has said there's a small possibility that the organic peroxide, which is used in the production of plastic resins, will get into floodwaters "but it will not ignite and burn."
The flooding in southeast Texas has severely affected oil and chemical plants. Many have shut down operations in the past few days, including, the Colonial Pipeline, which carries huge amounts of gasoline and other fuel between Houston and the East Coast. Valero and Motiva, the largest refinery in the country, have also closed some facilities.
'The worst is not yet over'
The heavy rain is over, but the devastation that Harvey unleashed in Texas has left unprecedented flooding and thousands of people vulnerable.
Many are trapped in flooded homes, and others who've taken refuge in shelters are unsure of their future. Across the state, families are searching tirelessly for missing relatives on the sixth day since the catastrophic storm made its first landfall as a Category 4 hurricane.
"The worst is not yet over for southeast Texas," Gov. Greg Abbott said in a news conference.
At least 37 deaths related to Hurricane Harvey and its aftermath have been reported in Texas. Among the dead are a Houston man who was electrocuted while walking in floodwaters and a mother whose body was floating about a half mile from her car. Rescuers found her daughter clinging to her body. The child is in stable condition after suffering from hypothermia.
Pleas for help
On Thursday, Federal Emergency Management Agency workers and firefighters will assess the extent of Harvey's destruction in the southwestern part of Houston, the nation's fourth largest city.
About 100 miles east, Beaumont residents could find themselves without running water Thursday morning. Local officials said the city's water pump station has failed and they need to wait until floodwaters recede to make any repairs.
In Port Arthur, desperate pleas of help piled up after residents woke up to rising waters when the storm made its final landfall Wednesday morning.
"All I have in my house is power. I have no food. I have no water. I only have power in my house. I don't have no way of getting around," Chatham said. "I'm stuck upstairs. It's just me and my dog. And I'm upstairs with my other neighbors. It's like five of us up here."
In the Houston area, officials said that more than 4,800 people have been rescued by the Coast Guard and local police while countless people are waiting for aid.
Dangers after the storm
Andrew Pasek inadvertently stepped on a live electrical wire as he walked in about 4 feet of water Tuesday. He was trying to get to his sister's house.
"He felt the charge and knew something was wrong right away and tried to shake it off right away," said his mother, Jodell.
The 25-year-old quickly asked a friend to get away from him "because if you do, you know, you will go too," he told his friend.
Pasek was electrocuted and died. His mother said no one tried to resuscitate him for an hour until the electricity was turned off.