HOUSTON, Texas -

Police are investigating the fatal shooting of woman who was at a teenager's birthday party in southwest Houston.

A Houston police sergeant tells KTRK-TV that someone ran by a home and fired an assault rifle at it. A birthday party for a 15-year-old was taking place at the time of the shooting.

The woman was in a bedroom when the bullet went through a window and struck her in the head.

Friends of the woman who were at the party told the station the woman had just found out she was pregnant.

Friends also say they didn't realize she was asleep in the back bedroom.

Police say they have no information on a suspect.