It has been a deadly weekend on metro Atlanta interstates after a string of wrecks in Clayton, Cobb and Fulton counties left four people dead.

The latest was an overnight crash in Clayton County. Two vehicles collided around 1:30 a.m. Sunday near the intersection of Ga. 85 and Ga. 138. The passenger in one vehicle was killed, while the driver in the second automobile was airlifted to a local hospital in unknown condition.

Clayton County police spokesman Phong Nguyen said traffic unit investigators probably will return to the scene Monday morning to continue their work. The cause of the accident and names of those involved were not immediately available.

Atlanta police are still probing two fatal crashes that occurred at different locations Saturday. The Fulton County Medical Examiner’s Office released the names of the deceased Sunday. However, the cause of the two accidents and any potential charges drivers could face were still unknown.

A city of Atlanta public works employee who died Saturday when a garbage truck rolled over was identified as Derryl Simmons, 54, of Decatur. Police said Simmons and a second worker were riding in the garbage truck around 2:30 p.m.

The garbage truck apparently overturned while exiting I-75 southbound at the Cleveland Avenue off ramp. The second worker was in critical condition at Grady Memorial Hospital.

The man who was struck and killed on I-85 north near the Ga. 400 intersection was identified as 20-year-old Peter James Judson. Atlanta police spokesman Officer John Chafee said a passenger (later identified by the Fulton County Medical Examiner’s Office as Judson) attempted to climb out of the window of a moving vehicle.

When the driver pulled over, the passenger got out and walked into traffic, where he was hit by another car, Chafee said. Judson died at the scene.

The driver of the car that hit him suffered minor injuries and was taken to an area hospital. No charges have been filed, although the investigation continues, Chafee said.

All northbound lanes of I-85 were closed for much of Saturday morning as a result of that wreck.

Also Saturday, Cobb County police said 17-year-old Rodrigo Solorio died around midday from injuries he sustained in a two-vehicle collision at Austell Road at Chamberlain Circle.

The driver of a black 2002 Range Rover, Wilson Marcellus, 45, of Douglasville, was traveling south on Austell Road. A blue 1989 Nissan 240SX driven by Solorio attempted to turn left in front of the Range Rover and was struck on the driver’s side.

Marcellus and a passenger in the Range Rover were both treated at Wellstar Kennestone Hospital for non-life-threatening injuries.

No charges are expected to be filed, according to Cobb police spokesman Officer Mike Bowman.

—Staff writer Aaron Gould Sheinin contributed to this report.