Between five and seven of the injured taken to Grady Memorial Hospital were in critical condition when they arrived, said hospital spokesman Denise Simpson.
Authorities have not released the name of the person killed. Shinkle said he wasn't sure how high or how long the bridge was or how much of it remained intact. He said all of the injured were construction workers who fell when the concrete structure collapsed and that early reports that people were trapped under the debris were incorrect.
Fifteen workers were taken to Grady and two others to another hospital, Simpson said. She said she believed the patients taken to Atlanta Medical Center had less serious injuries.
An Occupational Safety and Health Administration officer was on the scene, said OSHA spokesman Mike Wald. OSHA's job is to determine whether any safety standards were violated and the agency has up to six months to complete its report.
Dozens of police officers, firefighters and construction workers were at the entrance to the garden, which is next to a popular park for joggers and dog walkers.
The bridge is part of a walking trail and arched over a ravine.
Kate Brumback contributed to this report.