A two-vehicle collision involving a concrete truck shut down Ga. 400 north for nearly two hours Tuesday afternoon.

The wreck occurred about 12:45 p.m. at Settingdown Circle and Bottoms Road in north Forsyth.

A woman was initially pinned under the truck. She was eventually freed, but is in critical condition, according to Doug Rainwater, spokesman for the Forsyth County Sheriff’s Office. 

“We don’t know how her car got in front of the truck,” Rainwater said. “The truck’s probably four feet into her car.”

The woman was taken by helicopter to Grady Memorial Hospital, according to Forsyth County Fire Division Chief Jason Shivers. 

The southbound lanes of Ga. 400 south were also closed for about 15 minutes to allow the helicopter to land. Both sides of the corridor had reopened by 2 p.m.

The crash, the second involving serious injuries in a two-day span on the well-traveled traffic artery, remains under investigation.

Monday morning, a 60-year-old Cumming woman died when the 2009 Toyota Yaris she was driving struck a Freightliner tractor-trailer and a 2004 handicapped-equipped Ford Econoline van.

The collision occurred about 11:15 a.m. south of Pilgrim Mill Road (Exit 16).

Maria Josefa Martinez, a custodian at Shiloh Point Elementary School in south Forsyth, was pronounced dead at Northside Hospital-Forsyth.

Three passing motorists pulled the driver of the van, who had been previously paralyzed from the chest down and was trapped, from the vehicle after it caught fire.