Firefighters capped off the leak around 12:30. But the windy conditions were a concern. Once employees evacuated, a change in wind sent the fumes right toward them.
Employees at Golden State Vintners scattered Thursday morning, once they realized a serious problem. Many just arrived at the winery to deliver loads of grapes when they noticed the cloud.
Many left their lunch boxes and personal items behind when they rushed to a safety zone. Several truck drivers reported burning eyes from the toxic fumes.
Firefighters say the concentration of ammonia was at such high levels, hazmat crews had to wear full protective gear to fix the leak.
Sean Johnson with the Fresno Fire Department said, "The pipe was a little bit challenging because it was elevated and it was apparently a liquid pipe coming from the storage pipe for the anhydrous ammonia so it wasn't just a real simple patch."
Top executives at the winery say fire crews shut off power to the entire plant before assessing the problem. The company uses the chemical as part of their everyday operation.
Steve Roden said, "Like a lot of plants, in food processing, ammonia is used for refrigeration for cooling, and keeping things fresh."
Emergency crews say even though employees followed the evacuation plan, weather played a big part in the crisis event.
Johnson said, "It was blowing it away from the scene then it blew it back into the scene."
Shifting weather even forced crews to change the command post several times. The leak, couldn't have come at a worse time for the plant, it's the busiest time of year, known as crush season. So, shutting down production for even a few hours is a real setback.
Golden State Vintners makes wine for several hundred wine labels. Maintenance crews are cleaning up. The company must now permanently fix the leak. At this point, it's unclear if operations will continue Friday.