Four people were taken to the hospital after a crash on I-19 southbound near Pima Mine Road.
Lee Mayes, a spokesman for Rural/Metro Fire, said two were taken by helicopter and two by ground.
All four patients were taken to the hospital with critical injuries.
Rural Metro said they first received the call of a two-car collision at 5 p.m.
The four patients taken to the hospital were all from the same car.
The southbound lanes of I-19 have reopened at this time, according to the Arizona Department of Transportation.
