(Updated 12:40 p.m. Sunday)

A 6-month-old suffered critical injuries and the infant's parents were among four adults hospitalized Saturday night after a multiple-vehicle accident caused by a tractor-trailer shut down the southbound lanes on Interstate 75 in Cobb County for several hours. 

Cobb police spokesman Officer Joe Hernandez said late Sunday morning that the baby was taken to Children's Healthcare of Atlanta's Scottish Rite Hospital. 

The child's parents, Donald Morgan, 25, and Candice Morgan, 24, of Douglasville, were transported to Atlanta Medical Center with unspecified injuries. 

They were traveling southbound in a 2009 GMC Acadia that was stopped in traffic around 10 p.m. near the Windy Hill Road exit, Exit 260, because of road construction and lane closures near the Chattahoochee River. 

According to Cobb police investigators, a tractor-trailer driven by Henry Lipps, 59, of New Albany, IN, did not slow down and slammed into the rear of the Morgans' car, triggering a chain reaction involving two other vehicles.

Two cars ahead of the Morgans' vehicle was a 2002 Buick LeSabre in which Ramon Mcelrathbey, 24, and Cornelius Mcelrathbey, 21, both of Atlanta, were traveling. They were taken to Grady Memorial Hospital, also with undetermined injuries.

Joshua Merritt, 25, of Dacula and Cortney Chatham of Grayson were riding in a 2006 Toyota Highlander directly in front of the Morgans' car. Their vehicle was struck on the side, but they were not injured.

Lipps also was not injured.

Hernandez said the investigation is continuing. He said charges are expected to be filed. 

Cobb police are asking for the public to assist by calling 770-499-3987 with any information about the crash.