GLENDORA — Rescuers hospitalized four people, including one who was flown to a trauma center by helicopter, following a head-on crash on Foothill Boulevard early Saturday, authorities said.

The crash occurred about 9:10 a.m. in the intersection of Foothill Boulevard and Barranca Avenue, Glendora police Lt. Rob Lamborghini said.

One car contained four young women and was making a left turn from Foothill onto Barranca, police said. The other car, which contained only a driver, was heading in the opposite direction on Foothill.

The cause of the crash remained under investigation, but the cars met in a “near-head-on collision” in the intersection, Lamborghini said.

Three young women from the first car and the woman who was driving the second car were hospitalized with injuries which appeared to range from minor to moderate, the lieutenant said. One of the young woman was flown to a trauma center at Los Angeles County-USC as a precaution, though her injuries were not initially believed to be life threatening.