WIND GAP, Pa. - Authorities ordered about 5,000 people in and around this northeastern Pennsylvania town to evacuate for almost nine hours yesterday after a tanker truck carrying a hazardous chemical overturned.

The truck, hauling 33,000 pounds of corrosive hydrofluoric acid, overturned about 3 a.m. on Route 33 on the edge of Wind Gap, about 60 miles north of Philadelphia. Officials ordered an evacuation of 944 households around 7 a.m.

The driver was treated at a hospital and released, and one of about 200 people at an evacuation center at a high school was taken to the hospital for a condition unrelated to the accident, Northampton County spokesman John Conklin said.

Emergency crews reported liquid dripping from the tanker's valving or piping, forcing them to return in full-protection suits to stop the drip.

The truck was righted about 3:10 p.m. and the evacuation order lifted about a half-hour later, although the road remained closed in both directions.

In low doses, hydrofluoric acid can irritate the eyes, nose, and respiratory tract, according to the Centers for Disease Control and Prevention.

In higher doses, exposure can cause severe burns or even death, and inhalation can be fatal or result in chronic lung disease, the CDC says.

A number of animals in the area were rescued, including horses that were moved from several farms, Conklin said.