A Minnesota woman is accused of throwing her 11-year-old son off their apartment’s fourth floor balcony, leaving him with traumatic injuries, police said Monday.

Police responded to a call of an attempted suicide after another resident in the apartment complex thought the child jumped, reports say.

Investigators later learned that the 33-year-old mother pulled the boy out of bed, dragged him to the balcony and threw him over the railing.

The boy is expected to survive, but he suffered injuries including at least one broken leg, a fractured jaw and head injuries, St. Paul police spokesman Steve Linders said.

Police say the motive is still unclear.

The woman was arrested on suspicion of aggravated assault and malicious punishment of a child, but was not formally charged. The mother’s girlfriend was also questioned.