Two adults, including a father of 11, were killed and four children were injured when their SUV left the roadway and hit a tree early Monday in Cobb County.

Shortly before 4 a.m., a green Honda Passport fishtailed along Clay Road before leaving Clay Road and slamming into a Mulberry tree in Mary Caughorn’s yard. Investigators had not determined late Monday what caused the driver, 27-year old Katrina E. Morris, to lose control of the vehicle. Morris was killed in the crash, along with her front-seat passenger and the father of her three children, 28-year-old Rodney Smith.

Family members believe Morris and Smith and four children — all in the backseat — were traveling to her home in Powder Springs at the time of the crash, which happened near the intersection with Flint Hill Road. The Honda came to a stop after slamming into the tree and into a flower bed under its shady branches. Police said Monday it wasn’t known whether the four children were properly restrained, but two were in car seats, witnesses said.

Neighbors were able to pull the two youngest children, ages 1 and 3, from the wreckage. Firefighters were able to free the older two, a 5-year-old girl and 10-year-old boy, who were temporarily trapped. All four children were taken to Children’s Healthcare of Atlanta at Scottish Rite for treatment of serious injuries.

DeRodney, 10, and Yanni, 5, both underwent leg surgeries at Children’s Healthcare of Atlanta at Scottish Rite, Castleberry said. Aiden, 3, was in intensive care, but in stable condition, she said. One-year-old Amani had no visible injuries or bruises but was being kept at the hospital for observation.

— Staff writers Lauren Foreman and John Spink contributed to this report.

Read more on the wreck and the rescues on myajc.com.