An infant sustained critical injuries in a wreck that closed all southbound lanes of I-75 in Cobb County late Saturday.

Investigators say a tractor-trailer driver did not brake and struck three vehicles on the interstate at the Windy Hill Road exit around 10 p.m., Officer Joe Hernandez with Cobb County police said.

Traffic had come to a stop because of construction and lane closures at the Chattahoochee River, authorities said.

Investigators say the 1997 Freightliner, driven by 59-year-old Henry Lipps, of New Albany, Indiana, did not brake and collided with three vehicles -- the rear of a 2009 GMC Acadia, the side of a 2006 Toyota Highlander and the rear of a 2002 Buick LaSabre.

A 6-month-old in the Acadia was transported to Scottish Rite Hospital with critical injuries, Hernandez said. The infant's parents -- Donald Morgan, 25, and Candice Morgan, 24, of Douglasville -- were transported to Atlanta Medical Center with visible injuries, he said.

The two occupants of the Highlander -- Joshua Merritt, 25, of Dacula, and Cortney Chatham, 24, of Grayson -- were not injured, Hernandez said.

The driver of the LaSabre, 24-year-old Ramon Mcelrathbey of Atlanta, and his passenger, 21-year-old Cornelius Mcelrathbey, also of Atlanta, were transported to Grady Memorial Hospital with visible injuries, Hernandez said.

Lipps, the tractor-trailer driver, was not injured, the officer said.

The investigation is continuing and charges are expected to be filed, Hernandez said.

Police closed the southbound lanes of I-75 at Delk Road for more than two hours to clear debris and to investigate the wreck, Hernandez told the AJC.

The lanes re-opened around 1 a.m. Sunday.

Anyone with information on the crash should contact Traffic Services at 770-499-3987.