Seven people have died so far this weekend in area traffic crashes, authorities say.

The latest are three people killed about 5:30 a.m. today on Interstate 75 in Catoosa County. The Georgia State Patrol said the crash happened near mile marker 343 when the driver of an SUV switched from the center to the left lane, lost control and rolled several times in the median.

Three people in the SUV were not wearing seat belts and were thrown from the vehicle and killed, according to the GSP.

Trooper Cooper Burt said one victim lying in the road was struck by a tractor-trailer whose driver could not stop in time.

The crash is under investigation and victims' identities hadn't been released as of Sunday afternoon.

A motorcycle crash on Highway 58 about 8 p.m. Saturday took the life of Christopher Cobble, 30, of Harrison, according to the Hamilton County Sheriff's Office.

Cobble lost control of his 2006 Honda, left the road and hit a culvert, according to a news release. The investigation is ongoing.

And three Hamilton County residents died Saturday morning in Marion County when their Jeep left Big Fork Road and crashed about 4:30 a.m., according to the Tennessee Highway Patrol.

Nicholas S. Clayton, 20, and Emily F. Clayton, 21, both of Sale Creek, died along with 24-year old Annie E. Blevins of Chattanooga, according to a THP news release. The driver, Eric D. Blevins, 37, of Sale Creek, was airlifted to Erlanger hospital, the THP said.

Highway Patrol investigators think another vehicle might have been involved and they have asked the public for help in the investigation.