Miami ? A woman who died while attempting to reach the Florida Keys in a speedboat crowded with Cuban migrants sustained fatal head injuries, according to preliminary autopsy results released Sunday.

Amay Machado Gonzalez died and four others were injured Saturday when their boat, which held 31 migrants, ignored orders to stop and attempted to ram a U.S. Coast Guard vessel, authorities said. Coast Guard crew fired two shots into the vessel’s engine to disable it.

The one-page report said Gonzalez also sustained blunt injuries to her arms, legs and back. Authorities said she was crammed into the small boat and jostled in the rough seas.

“There was no way for these people to brace themselves against the impact of the boat slamming into the rough seas,” Coast Guard Capt. Phil Heyl said in a statement.

The Coast Guard intercepted the boat around 6:30 a.m. about 4 miles south of Boca Chica, Coast Guard officials said. Gonzalez was pronounced dead as she was being transported to a hospital.