Louisiana ? Six cars of a freight train derailed Saturday in Lafayette, causing a hydrochloric acid leak that forced thousands of people to leave homes, businesses and a nursing home within one mile of the wreck.

The spilled acid sent a toxic cloud over the area, and at least five people, including two railroad workers, were taken to a hospital and treated after complaining of skin and eye irritation, said Lafayette Parish sheriff’s Lt. Craig Stansbury.

A nursing home with 161 residents was evacuated, said Dr. Jimmy Guidry the state health officer, said. About 35 of the residents deemed too frail to travel were taken to area hospitals, he said.

Police walked door-to-door notifying residents of the mandatory evacuation in an area with an estimated population of 3,500 people. “We’re advising them to take enough supplies for approximately 48 hours,” Stansbury said.