California ? Four teens were charged Wednesday in the alleged gang rape and beating of a 15-year-old girl outside her high school homecoming dance in Northern California, in an attack that has generated widespread outrage.

All four — ages 15, 16, 17 and 19 — were charged with rape and enhancements that they acted in concert, which could make them eligible for life in prison.

The minors each face one count of felony rape with a foreign object. The 16-year-old also faces robbery charges. They were charged as adults because of the severity of the crime, Richmond Police Lt. Mark Gagan said.

Besides rape, the 19-year-old, Manuel Ortega of Richmond, was charged with robbery and assault causing great bodily injury.

The victim was released from the hospital Wednesday.