WARDEN, Wash. (AP) — A massive fire at a potato plant in the town of Warden in Grant County brought fears of an exploding ammonia tank, forcing the evacuation of nearly a third of the town for several hours.

The fire broke out at the Washington Potato Plant around 5:30 p.m. Thursday in one of the dehydrators, according to Kyle Foreman with the Grant County Sheriff’s Office.

Employees made it out safely as the flames spread, eventually engulfing much of the plant. Inside the burning building was large ammonia tank that firefighters feared could explode and send a toxic cloud over the region.

Residents returned home around 1 a.m.