ATLANTA – We are learning more details about the construction that quickly reopened I-20 westbound after the interstate buckled Monday afternoon.

After the unexpected buckling of the road surface and subsequent lane closure on Interstate 20 westbound between Flat Shoals and Gresham Roads on Monday, Georgia DOT crews worked through the night and opened all lanes to traffic by 6:30 a.m. on Tuesday—fewer than 19 hours after the first reports of the incident.

The damage was caused by utility work being performed beneath the roadway by Atlanta Gas Light (AGL).

“AGL had a permit to jack and bore 525 feet of a 36-inch-high pressure steel gas main under I-20 and also 920 feet along Cook Road, which runs parallel to I-20,” said State Utilities Engineer Patrick Allen. “Both the state and district utilities offices did a thorough and in-depth review of the permit request, deemed the request met all state requirements and that the work was a safe distance beneath the roadway. As a result, a permit was granted to AGL in August 2016.”

A motorcycle and car traveling along I-20 hit that section of road and went airborne. The motorcyclist landed about 200 feet from the road failure and was transported to the hospital in critical condition. The car traveled about 15 feet before landing back on the ground. Amazingly, that driver was not injured.

Capt. Eric Jackson with DeKalb County Fire called the road failure a "once in a lifetime experience."

Monique Burston was right there when the road buckled and a motorcycle went airborne. "I saw it rise up like a tombstone coming out of the ground," she told 11Alive's Duffie Dixon Monday night.

"I was coming off of 20 and the motorcycle guy, he was riding over and the motorcycle threw him up like 10 feet in the air."

Laura Creekmur, a spokesperson for Atlanta Gas Light, said they are aware of the situation and currently investigating. She stressed that the incident was not natural gas related.

By 3 p.m. Monday, GDOT engineers and the contractor determined that the drainage system (a line of pipe) had to be replaced, and they began the arduous work to break up and remove large slabs of concrete and dirt, the most time consuming part of the work. By 4:30 p.m., crews secured the proper piping, began laying the pipe and making the repairs.

“At approximately 9:30 p.m. the pipe had been placed and compaction completed and crews began the final stages of prepping the surface to pour the concrete slabs for the roadway repair,” said Kathy Zahul, Metro Atlanta District Engineer.

Concrete slabs were poured an hour ahead of schedule, completing that process at 1 a.m. on Tuesday. The use of “rapid setting concrete” for fast curing and drying of the concrete allowed the roadway to be opened to traffic quicker than if regular curing concrete was used.

By 4:50 a.m., crews cut joints in the concrete slabs to allow for contraction and expansion throughout the life of the pavement. This process controls cracking and deterioration of the concrete, allowing for a longer service life and reduced maintenance needs.

After the roadway was temporarily striped, it was completely opened to traffic at 6:30 a.m.

“I cannot overemphasize how proud we are of our employees and their commitment to the motorists of Atlanta,” Georgia DOT Commissioner Russell R. McMurry, P.E. said. “This was something that could not be planned for and, once again, our team rose to the challenge and did what needed to be done.”

GDOT will pursue reimbursements for the costs and expenditures related to the repair of damage to I-20 westbound lanes.

The Georgia Department of Transportation encourages motorists to pay attention whenever they drive – to put down the phone, buckle up and drive alert. And in roadway work zones - slow down, watch for workers and always expect the unexpected. Work zone safety is in your hands.