The deadly collision, which also claimed the life of their mother’s friend and her 13-year-old son, occurred July 12 on Interstate 10 just outside Quartzsite, Arizona.

Investigators with Arizona’s Department of Public Safety said that as traffic was slowing down on the highway because of a repaving project, utility truck carrying a load of asphalt slammed into the rear of the family’s car causing a five-vehicle crash that left all six passengers in the car dead.

The Perez girls’ aunt, Kasandra Tunchez remembers the joy the sisters brought to the entire family, especially her brother Vincente Perez, the girls’ father.

“My brother is hanging in there,” she told KTLA’s Shelby Nelson. “We as a family have come together to support him.”

Tunchez described the sisters, 12-year-old Olivia, 11-year-old Emalynn and 8-year-old Giana, as incredibly smart and respectful.