An ammonia gas leak in Oklahoma has led to the evacuation of hundreds of residents and the hospitalization of at least 36 individuals, according to local authorities.

The incident occurred in Weatherford, a city with a population of approximately 12,000 people, situated about 70 miles west of Oklahoma City. The leak originated from a tanker truck.

“At around 10 p.m. last night, a tanker truck started leaking ammonia. It stopped in a hotel parking lot here in Weatherford. The situation escalated, prompting the evacuation of the hotel, several nearby residences, and other areas,” explained Mike Karlin, Weatherford’s emergency manager and director of public safety, during an interview with Fox News Digital on Thursday.

“We had 36 individuals who required medical attention at the local hospital. Out of those, 11 were subsequently transferred to hospitals in the Oklahoma City metro area,” he further stated.

In response to the evacuation, temporary shelters were set up with beds ready for evacuees, as seen on Thursday, November 13, 2025, in Weatherford, Oklahoma. (KOKH)

“Currently we are just trying to dissipate the remaining part of the anhydrous ammonia and hoping to get residents out of the shelter and back to their homes and businesses just as quickly as we can,” Karlin also said.

At least 500 to 600 people were in a shelter as of Thursday morning, according to authorities.

“Air quality has reached safe levels and we are releasing the shelter in place order for the area,” the Weatherford Police Department later said in a statement. “Residents can return home at this time. Residents are encouraged to air out their residences by opening doors and windows. If you were exposed to any chemicals remove your clothing and thoroughly wash your body with soap and water. If you are feeling ill, call 911 immediately. 

Police said earlier in the day that, “Weatherford Public Schools has closed down all campuses today.” 

Weatherford Police Chief Angelo Orefice said at a press conference Thursday it remains unclear how the leak happened, but investigators suspect it might have occurred due to a mechanical failure on a valve or a faulty seal on the truck. 

Evacuees are seen on Thursday, Nov. 13, 2025, on the campus of Southwestern Oklahoma State University in Weatherford, Okla. (KOKH)

Southwestern Oklahoma State University in Weatherford also announced that all in-person classes were canceled Thursday as a result of the “anhydrous ammonia leak.”

“First responders on scene have recommended that all students in SWOSU on-campus housing shelter in place due to the fumes,” the university said.

Anhydrous ammonia is used as a fertilizer to help provide nitrogen for corn and wheat plants, according to The Associated Press. If a person touches it when it is in gas or liquid form, they could be burned.

Authorities said the air quality was being monitored and that the tanker truck was no longer spewing gas, but that a lack of wind was slowing efforts to dissipate it. A number of agencies were on hand to assist, including hazmat crews and an Oklahoma National Guard unit that supports first responders during emergencies.

An explosion at a chemical plant near Yazoo City, Miss., last Wednesday resulted in an ammonia leak.  (WDBD-WLBT)

Last week, an anhydrous ammonia leak caused by an explosion at a plant north of Yazoo City, Mississippi, prompted evacuations for nearby residents.