The El Paso Fire Department's Hazmat and Decontamination teams found the spill inside Southwest Refrigerated Services at 12190 Rojas Drive.

Employees at nearby businesses said they too smelled the fumes inside their plant. "Basically it was just a very strong odor. At first we didn't realize what it was," said Luis Rosales, who was evacuated from the Wrangler Distribution Center.

Emergency crews later learned a maintenance worker accidently spilled several gallons of ammonia while he was changing out a relief valve. "Some of the product spilled. However, it was caught in a bucket," said battalion chief Greg Burns.

He said the refrigerated storage facility houses about 10,000 pounds of ammonia, and as a precaution they had a larger than normal response. Streets were closed off for several blocks and nearby facilities were evacuated.

"Eventually it (the fumes) started taking over the whole plant and we started smelling ammonia. Some people complained of irritation in the eyes, others couldn't breathe," said Rosales.

No one was hurt in the incident and employees returned to work by 11 p.m.