A major ammonia spill in Weatherford, Oklahoma late Wednesday night led to mass evacuations and dozens of hospitalizations, after a tanker truck leaked chemicals across the area. Authorities confirmed that roughly 1,000 residents were displaced as emergency teams worked through the night to contain the leak.
Leak Began After Faulty Valve on Tanker Truck
The incident started shortly after 10 p.m., when a semi-truck parked at the Holiday Inn on East Main Street was found leaking ammonia. Weatherford Police Chief Angelo Orefice said the driver returned to the vehicle and discovered the spill, which he believes stemmed from a faulty valve or defective seal.
Chief Orefice said an evacuation zone covering almost a square mile was established around the hotel as crews began containment efforts. The truck remained at the scene Thursday morning while cleanup operations continued.
36 People Hospitalized, Four in Critical Condition
The ammonia leak sent fumes throughout the area, leading to widespread breathing difficulties.
Orefice reported that four people were mediflighted to Oklahoma City hospitals in critical condition, while 11 others were treated for less serious injuries. Another 33 residents were treated in Weatherford for minor exposure symptoms.
A separate report from local officials confirmed that 36 individuals were hospitalized in total, with hundreds evacuated from homes, senior centers, and nearby buildings.
Authorities Say Residents Can Begin Returning Home
By Thursday morning, officials said ammonia levels had fallen to safe limits. Businesses west of East Washington Street were allowed to reopen.
During a press conference, Orefice explained: “We don’t have any information that the truck was in an accident. Right now, the best that we can determine is that it was either a mechanical failure with a valve or it was a faulty seal.”
He advised residents to continue monitoring their health following the spill: “We are asking the public to keep watching each other, loved ones, if they’re having breathing problems, to call 911, or go to the emergency room.”
Families were told they could open windows to help ventilate their homes, though areas near the hotel will stay blocked off. Cleanup could last several days as crews monitor air quality.
What Is Anhydrous Ammonia?
The leaked chemical, anhydrous ammonia, is widely used as an agricultural fertilizer. According to the Minnesota Department of Agriculture, the compound contains nitrogen and three hydrogen atoms.
Because it contains little to no water, the chemical aggressively pulls moisture from anything it touches, including the eyes, throat, lungs, and skin. Exposure can cause:
- Severe breathing problems
- Tissue dehydration
- Caustic chemical burns
- Frostbite
This makes leaks especially dangerous in residential areas.
About Weatherford, Oklahoma
Weatherford is located in Custer County, along the historic Route 66 corridor. It is also home to Southwestern Oklahoma State University (SWOSU), which served as a temporary shelter for evacuees during the emergency.
