An emergency evacuation order was lifted nearly 12 hours after a fire began at a food-processing plant east of Windsor, Ont. on Friday morning.

On Friday morning, the mayor of Tecumseh declared a local state of emergency as the fire that started at approximately 2 a.m. tore through the Bonduelle plant at 1192 Lacasse Blvd. The state of emergency has also been lifted.

Although the amount of damage will not be determined until a formal investigation is complete, representatives of Bonduelle said that production delays are likely due to the fire.

Earlier in the day, firefighters said they suspected an electrical problem was to blame, but the cause of the fire has not been confirmed.

The roof and some of the walls of the plant have collapsed, and large plumes of black smoke can be seen as far away as Michigan.

At one point, at least 20 fire trucks were on scene, authorities said.

"We entered the building. The visibility was zero. We pulled the crew out for safety reasons. Shortly after that we saw flames, maybe 20 to 30 feet going through the roof at that point," Tecumseh Fire Chief Doug Pitre said on Friday morning.

No injuries have been reported, but Pitre was concerned about the large amount of ammonia that has been burning.

The ammonia was isolated and monitored to ensure that no chemicals were released into the air, Pitre said.

However, Emergency Management Ontario issued a red alert due to the hazardous materials.

As a precaution, residents in the area of the plant who live between County Road 22 to the south, St. Thomas Road to the north, Lesperance Road to the west and Manning Road to the east were asked to leave their homes on Friday morning.

Tecumseh Arena and St. Joseph School were used as shelters for those living in the evacuated areas. Approximately 1,300 homes were affected, but officials say that residents can now return home.

The same plant caught fire in 1973, and the blaze caused $10,000,000 in damages, according to the Tecumseh Fire Department.

The plant employs 150 full-time employees and 700 seasonal workers. Bonduelle said that 110 farmers provide goods to the plant.

With files from CTV Windsor