"If somehow the foam blanket might have been exposed, exposing a vapor and there's hot metal that's been burning for four days, it can reignited very quickly. They're in a position to suppress that very quickly," said Mark Sloan, Harris County Emergency Management Coordinator.
Unlike the past three days, crews are in an offensive position to respond now. "Just because the fire is out there is still product in the holding tank that has to be dealt with. You still have the same components in regards to the volatility of products that could reignite," said Deer Park Mayor Jerry Mouton.
The city's government Twitter account said the flare-up was contained within about 30 seconds by staged firefighting equipment.
There is literally a trickle down impact. Pictures show the runoff into nearby waterways, a big concern for those who make their living from the Ship Channel and Galveston Bay.
Tests are being run by the EPA for potential pollution in the Ship Channel. They have said air monitoring readings have not detected any hazardous levels of concentration.
The investigation won't make significant strides forward until all of the material is removed and the remaining debris has cooled off. "There will be accountability. There will be and there is an ongoing investigation," said Harris County Judge Lina Hidalgo.
But getting to the root cause of this disaster will take time.
The tank fires burned, at one point, chemicals in up to eight tanks for more than three days.
The city also stated small flare-ups are expected for incidents of this scale.
The City of Deer Park received confirmation Wednesday of a small flare-up at the site of the Intercontinental Terminals Company fire incident.— City of Deer Park (@DEERPARKTXGOV) March 20, 2019
According to Emergency Services Director Robert Hemminger, who spoke with first responders on scene, the flare-up was contained within approximately thirty seconds using staged firefighting equipment.— City of Deer Park (@DEERPARKTXGOV) March 20, 2019
Hemminger indicated that in fire incidents of this scale, small flare-ups are expected and first responders plan to address these issues as they occur.— City of Deer Park (@DEERPARKTXGOV) March 20, 2019
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Tuesday night, four tanks were burning as a large flash of fire rose from the facility. The cause of the fireball was not immediately known.
ITC INFERNO: Harris Co. Sheriff's Office helicopter gets closer shot of burning tanks
Wednesday morning, ITC officials released a statement saying that crews were able to extinguish all the fires as of 3 a.m.
"Crews continue to spray foam and water on the tanks to facilitate cooling and prevent reigniting of the remaining material," the statement read.
While the fires are out, steam and smoke may still be visible and there is a possibility that fires could reignite.
READ FULL ITC STATEMENT BELOW
On Tuesday, various officials stood firm on the public safety aspect of the large plume of black smoke hovering over southeast Texas. Despite the various chemicals being burned, both state and ITC officials said there was nothing toxic in the smoke in spite of reports of small debris falling.
WATCH: Time-lapse video closer to Deer Park fire
Meanwhile, several school districts near the facility cancelled classes due to the ITC fires.
Some of the districts include Deer Park ISD, Channelview ISD and La Porte ISD. San Jacinto College also cancelled classes today.
HISD released a statement saying that district officials continue to monitor air quality reports but will be operating under normal schedules.
During a press conference Tuesday morning, ITC apologized to the community as concerns grew tremendously since the fires started Sunday around 10:30 a.m.
WATCH: ITC apologizes to residents for facility fire
"This isn't an event we wanted or planned. Many of my employees work in the city of Deer Park, they live in Deer Park, they're out there fighting this fire the best they can," ITC spokeswoman Alice Richardson explained.
"They are residents. I would guess that probably 30 percent live in Deer Park in La Porte. They're concerned. Their families are concerned, so of course ITC would apologize to any of them," Richardson continued.
The company claims testing done by independent contractor CTEH are below levels that would represent a public health concern.
RELATED: What was burning inside the tanks at the ITC facility
ITC officials say the first tank that caught fire Sunday contained NAPHTHA. The fire then spread to a second tank with XYLENE. Both are gasoline components.
Officials said the components are in gas blend stocks used in the production of finished gasoline and base oil used for machine lubrication.
NAPHTHA can cause irritation to eyes and the respiratory system. It affects the central nervous system and is harmful and even fatal if it is swallowed.
XYLENE may also be fatal if it is swallowed and enters the airway. It can cause skin irritation.
Another tank that caught fire early Monday morning contained Toluene, which is used in nail polish remover, glue and paint thinner, plant officials told Eyewitness News.
According to the Occupational Safety and Health Administration, Toluene is used in many products and workplaces like printing operations, manufacturing facilities, construction sites and nail salons.
SEE ALSO: Health experts on big smoke plume: 'Stay inside and away'
The Deer Park Office of Emergency Management released a message on social media about a hotline people can call because of an increase of claims following the incident at ITC.
No serious injuries have been reported as a result of the incident. ITC officials said they are continuing to monitor the air, but as of Wednesday's update, readings are currently well below hazardous level.
"We continue to prioritize the safety of our surrounding community, our employees and the environment," the ITC statement read.