By Daniel Kelley

PHILADELPHIA (Reuters) - A mother and daughter have died from burns they suffered when a propane tank exploded in the family's food truck in Philadelphia earlier this month, authorities said on Thursday.

Jaylin Landaverry Galdamez, 17, and her mother, Olga Galdamez, 42, each were burned on more than 50 percent of their bodies from the explosion on July 2, authorities said.

They died just days apart, the mother on July 20 and the daughter on July 22, said Jeff Moran, spokesman for the Philadelphia Medical Examiners Office.

The pair was working in the truck at the time of the blast, which sent a propane tank flying 150 feet and injured nine other people.

Surveillance video from neighboring businesses showed a ball of flame scorching cars and a telephone pole as it flew across a street in the densely packed neighborhood of Feltonville.

The truck, named La Parrillada Chapina, was run by the Guatemalan family, according to local media.

Executive Chief Peter Crespo of the Philadelphia Fire Department said the cause of the blast was still under investigation.

(Editing by Ellen Wulfhorst and Sandra Maler)