In an update on Friday morning, Harris County Sheriff Ed Gonzalez said the two victims were removed from the scene and taken to the Harris County Institute of Forensic Sciences.
HCSO confirmed that team members went to the scene overnight, and no additional victims have been found so far.
The leak happened at about 4:40 p.m. Thursday at the Pemex facility off of Highway 225.
Emergency responders waited until the chemical levels dropped low enough for investigators to safely enter the unit at the center of the leak.
ORIGINAL REPORT: 2 dead, at least 35 injured after chemical release reported at refinery in Deer Park, officials say
2 dead, at least 35 injured after chemical release reported at refinery in Deer Park, officials say
Authorities confirmed two employees were killed and another 35 were exposed to the chemical. It's unclear how serious those exposures were.
The chemical hydrogen sulfide is a colorless gas known for its pungent "rotten egg" odor at low concentrations. It is extremely flammable and highly toxic and can cause mild headaches, eye irritation, unconsciousness, and death, even at low concentrations.
Crews hope to enter unit at center of deadly Deer Park chemical leak
Neighbors said they smelled "rotten eggs" from miles away on Thursday.
So far, the cause of the leak is still unknown.
"Some workers were working on a flange of some kind when there was a gas leak of H2S, which was hydrogen sulfide," Gonzalez said. "We believe, at this point, that there are two persons deceased on scene."
Thursday's chemical leak was the second scare for people in Deer Park in less than four weeks. A pipeline fire last month burned for four days.
The shelter-in-place orders were implemented for Deer Park and Pasadena around 6:30 p.m. Thursday, and have since been lifted.
ABC13 spoke to Deer Park and Pasadena residents, who said they were completely unaware of what was happening and are questioning why no alerts were sent to their phones.
In a social media post, the City of Deer Park acknowledged that their emergency alert system was having issues and that some people may not have received the notifications.
ABC13 spoke to some people at a bowling alley who were not pleased that they had no idea that a dangerous chemical had been leaked into the air.
"I was at work, and I had no idea. I found out through Facebook, and I was like, 'I wonder if any of my loved ones could have been harmed or anything like that.' It kind of reminded me of the ITC fires. It kind of gave me flashbacks," one resident said.
Azell Carter, the coordinator for Pasadena's Office of Emergency Management, said a technology error prevented their messaging from reaching everyone who signed up for the city's alerts. He said the messaging did reach 95% of people in the shelter-in-place zone but was not widely received.
"That's why we have redundancy with our sirens, especially with shelter-in-place, so if we do have some type of issue where the message doesn't go out as far or as broad as we would like for it to go out, we do have our sirens that sound as well," Carter said.
He said they are doubling the number of sirens in the city to 30 by the end of December.
Since the error with their emergency alert systems, both Deer Park and Pasadena officials have said they fixed the problems.
ABC13 checked Pemex's environmental record with the EPA and could only find one violation from 2022, which was for the "Lead and Copper Rule." The violation was listed as resolved.
Pemex, based in Mexico, has not yet said anything about how the leak happened. The refinery processes crudes from several countries and produces a range of products, including gasoline, aviation fuel, diesel fuel, and ship fuel.
"(Thursday) was a tragic day for us here at PEMEX Deer Park," Guy Hackwell, the CEO of Pemex Deer Park, said in a statement Friday afternoon. "We are deeply saddened that two people died at our site and that other workers were hospitalized. Our thoughts are with the loved ones of the deceased and the workers who were impacted. Our Employee Assistance Program (EAP) is available for all employees needing help."
Harris County Pollution Control said they conducted air monitoring outside the fence line of the Pemex on Thursday and did not detect anything harmful. The agency said they continued monitoring on Friday.