A hazardous ammonia gas leak in Oklahoma led to the evacuation of hundreds of residents and resulted in at least 36 individuals being hospitalized, according to local authorities.

The incident occurred in Weatherford, a city with a population of around 12,000, situated approximately 70 miles west of Oklahoma City. The leak originated from a tanker truck, prompting immediate safety measures.

As Mike Karlin, Weatherford’s emergency manager and director of public safety, explained to Fox News Digital, “Around 10 p.m. last night, a tanker truck developed a leak and pulled into a hotel parking lot here in Weatherford. The severity of the leak necessitated the evacuation of the hotel and several nearby residences.”

Karlin detailed the aftermath, stating, “We had 36 victims transported to the local hospital. Of those, 11 were further transferred to metro-area hospitals in Oklahoma City for additional care.”

In the midst of the crisis, emergency shelters were set up for evacuees. A photograph from November 13, 2025, shows beds prepared for residents displaced by the leak, highlighting the community’s response to the emergency.

“Our current focus is on dissipating the remaining anhydrous ammonia,” Karlin noted. “We aim to return evacuees to their homes and businesses as quickly as possible.”

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.