Girl, 11, Killed After Falling Out of Party Bus

An 11-year-old girl was killed after she fell out the emergency window of a party bus during a birthday celebration in downtown Portland, Ore.

The child, who was identified as Angie Hernandez, was leaning against the emergency exit. When the bus turned, the window opened and Angie fell into the road, family members told ABC News' Portland affiliate KATU-TV.

Hernandez was pronounced dead at the scene.

Portland police spokesperson Robert King said the death was a tragic accident.

"Those emergency exits are designed to be secured and closed and locked," King told KATU. "One of the questions I know investigators will be asking is how it came to be open, whether it was faulty."

The party bus was full of 20 to 30 people, the majority of them children, who were en route to a quinceanera party, a Latino celebration marking a girl's 15 th birthday.

Another birthday celebration aboard a party bus ended in tragedy last month.

Daniel Fernandez, 16, of Queens, New York, was on a double-decker party bus carrying 65 teens to a birthday party in New Jersey when he stuck his head out of the emergency hatch, struck his head on an overpass and died.

In July, a 25-year-old California woman died after she fell out of a party bus on her way home from a concert. A second woman fell out of the bus and sustained moderate injuries.

In 2010, a 19-year-old died in a car crash after drinking aboard a party bus. California Gov. Jerry Brown signed a new last week requiring chaperones and ID checks on all party buses carrying underage passengers.

ABC News' Sydney Lupkin contributed to this report