Authorities say 11 people have been injured after a tram overturned at Kartchner Caverns State Park in southeastern Arizona.
Park manager Christopher DeMille says three people were transported to hospitals in Benson and Sierra Vista with serious but non-life threatening injuries.
DeMille says the three-car electric tram was headed up the hill while taking park visitors to the caverns about 11 a.m. Friday. He says something went wrong and the tram fell off to the side of the road, ejecting some of the passengers.
Authorities say the Park Service is investigating the cause of the accident.
Kartchner Caverns is a series of live limestone cave formations that were discovered in 1974 but didn't become public knowledge until 1988 when the park purchase was approved. The park opened in 1999.