Family members say they took a 13-year-old Utah girl off life support three days after a train accident that killed her sister and another girl.
The family wrote on a blog Tuesday that doctors said Savannah Webster would not recover further from severe brain injuries.
Hospital officials confirmed Wednesday that she had died.
Savannah's sister, Kelsea Webster, and friend Essa Ricker, both 15, died Saturday after they were hit while taking photos near Covered Bridge Canyon.
Utah County deputies say the girls were caught between two trains and the wind from one train may have blown them into the path of the other.
A Union Pacific spokesman says the eastbound engineer tried to stop when the girls were spotted on the tracks but was unable to do so.