Anhydrous ammonia leaked from a pipe for more than two hours in the south-central Iowa town of Lacona today. The entire town, which has around 350 residents, was evacuated.

Warren County Emergency Management Coordinator Mahala Cox says it’s unclear what triggered the leak. “We do know that it was a burst pipe. A HAZMAT team came in and shut down the valves to cut the leak off,” Cox said. The leak was first reported just after 10 a.m. Lacona residents were sent to a school several miles outside of town.

“We asked for the whole town to be evacuated mainly as a precaution,” Cox said. Many of the town’s residents were notified of the chemical leak through an automated phone call system. Firefighters also went door to door warning people within a block of the tank farm located at the South Central Co-Op.

Cox says no one was seriously injured but authorities did convince one couple that lives closest to the co-op to visit a hospital for a checkup. Firefighters from Lacona, Milo and Indianola doused the tank farm with water to dampen fumes from the leak, which the Des Moines  HAZMAT team helped shut down.

Residents were allowed back in town around 1 p.m.