Story highlights Shooter has been identified as 19-year-old Geddy L. Kramer of Acworth

Kramer died "from an apparent self-inflicted gunshot wound," police spokesman says

Six people are taken to Wellstar Kennestone Hospital

A FedEx package handler went on a shooting rampage early Tuesday at his workplace in suburban Atlanta, wounding six people before turning the gun on himself, officials said.

"That individual is deceased here at the scene," Cobb County Police Sgt. Dana Pierce told reporters. Police were sweeping the area with search dogs to ensure no secondary devices had been planted.

Authorities identified 19-year-old Geddy L. Kramer of Acworth as the shooter. His body was found near a shotgun, Pierce said.

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"That was the only weapon that he had at that time," Pierce said.

The warehouse is located in Kennesaw, Georgia, about 21 miles northwest of downtown Atlanta.

"Numerous" 911 calls from inside the half-million-square-foot package and delivery facility alerted police to the shooting at 5:54 a.m., Pierce said.

Photos: Photos: FedEx shooting in Georgia Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – Law enforcement officers respond to shootings at a FedEx facility in Kennesaw, Georgia, on Tuesday, April 29. Police say a FedEx package handler went on a rampage Tuesday, wounding six people -- one of them critically -- before fatally shooting himself. Hide Caption 1 of 6 Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – FedEx employee David Chumley, left, talks to a Cobb County police officer Tuesday, April 29, after he was bused out of a blocked-off area because of the shootings. Hide Caption 2 of 6 Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – Cobb County police block off a road after the early morning shootings at the FedEx facility on Airport Road. The facility is a large warehouse about 21 miles northwest of downtown Atlanta. Hide Caption 3 of 6 Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – A Cobb County police officer escorts a FedEx employee as he leaves the blocked-off area. Hide Caption 4 of 6 Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – Emergency officials respond to the scene on Tuesday. Hide Caption 5 of 6 Photos: Photos: FedEx shooting in Georgia FedEx shooting in Georgia – Police were sweeping the area with search dogs to ensure no secondary devices had been planted. Hide Caption 6 of 6

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The victims were taken to WellStar Kennestone Hospital, where an emergency room doctor involved in the response said three were in critical condition.

EMS officials warned the hospital at 6:26 a.m. to prepare for the victims' arrival, Dr. Michael Nitzken said. By 7 a.m., the six patients -- all of whom had suffered multiple gunshot wounds -- had arrived.

Without naming them, Nitzken identified them as:

-- a 28-year-old man in critical condition after undergoing surgery;

-- a 52-year-old woman in stable condition after undergoing surgery;

-- a 22-year-old man in stable condition;

-- a 38-year-old man in stable condition;

-- a 42-year-old woman who was treated and released;

-- a 19-year-old man who was treated and was to be released.

Two of the patients -- the 28-year-old man and the 52-year-old woman -- suffered life-threatening injuries and the man was placed on mechanical ventilation, he said. "They appeared to be shotgun blast effects, with multiple, small projectiles," Nitzken said.

Their arrival at the level-two trauma center coincided with a shift change. "That proved to be to our benefit," the doctor said, because the staff was double what it typically would be. "We're trying to make the best of a bad outcome."

FedEx spokesman Scott Fielder told CNN that the situation had stabilized "and we are focused on the needs of our team members and cooperating with the law enforcement investigation of this tragedy."