California Highway Patrol (CHP -A woman who law enforcement said was driving the SUV that her two children were in before they hopped out and were killed by another driver on a Vista freeway was arrested on suspicion of DUI.

California Highway Patrol (CHP) said the incident was reported Sunday evening when the children – a 10-year-old boy and a 16-year-old girl – were struck by a Nissan Sentra on SR-78. According to CHP, the crash happened when a GMC Yukon pulled to the right shoulder of the freeway and the two children stepped out of the vehicle. A Nissan Sentra traveling eastbound on SR-78 struck the children.

Both children were declared dead at the scene, CHP said. Officials said on Monday morning that the family was homeless at the time of the incident.

The children’s father and an aunt told NBC 7 on Monday that Alan Gerardo Aguilar, 10, and Amy Monserrat Beltran, 16, were killed in the incident. The also said that the family went to a park on Sunday to sell bracelets to get a present for Father’s Day, adding that there were six kids in the car when the pair were killed. The father told NBC 7 that the children were attempting to retrieve Alan’s backpack when they died.

The driver of the Nissan, who was only identified as a 41-year-old woman from Vista, stayed at the scene.

As the investigation progressed, the woman driving the Yukon was arrested in connection with the death. The driver, who officials identified as Sandra Ortiz, 33, of Vista, faces charges that include DUI, gross vehicular manslaughter while intoxicated and child endangerment.

The investigation is ongoing. Anyone with information on the case is encouraged to contact CHP’s Oceanside-area office at 760-643-3400.