Note: This article contains troubling details.

Harrowing 911 audio reveals a witness’ account as a gunman unleashed a barrage of bullets on the Centers for Disease Control and Prevention, including the moment the first responding officer was fatally shot.

The 8-minute, 14-second call, released Thursday by Atlanta police, provides new details about the Aug. 8 attack that killed DeKalb County police Officer David Rose. The incident, which began shortly before 5 p.m. on a Friday, forced a lengthy lockdown of Emory University and the CDC and left the public health agency’s buildings riddled with bullet holes.

“There’s an active shooter. Please, there are no police here yet,” the panicked man said at the start of the 911 call.

The caller, who is not identified, hurriedly relayed to emergency operators what he was seeing as he watched from an unspecified location with a clear view of the shooter. A hail of gunfire was heard in the background through much of the call.

GBI Director Chris Hosey would later say investigators found more than 500 shell casings at a CVS pharmacy across the street from the CDC, where the shooter had positioned himself, along with five guns.

Within a minute, the caller said he could see a DeKalb officer arrive, later identified as Rose.

“You see a DeKalb unit?” the operator asked.

“Yes, but he’s going to put himself in very much danger right there,” the man frantically warned.

Within 1 second, at least a dozen shots were fired.

“He’s probably taking fire at this point,” the man said. “He’s shooting at the, he’s shooting at the officer!”

“Officer is trying to get to safety,” he added, quickly followed by confirmation the “officer’s hit. Officer is down. … I can’t go over there and get him.”

Authorities confirmed Rose was the first officer to arrive at the scene. He was rushed to Emory University Hospital, where he died a short time later.

The funeral for Dekalb County police officer David Rose was held Aug. 22. (Arvin Temkar/AJC)

Just as the caller noted Rose had been hit, the sound of ambulance sirens joined the continuous gunfire.

“They’re going to be under very big fire here. The guy’s got, it looks like, one long (gun) and plenty of rounds of ammunition,” the witness warned the operator.

“Please don’t send those EMS guys there,” he pleaded.

For 8 excruciating minutes, the man updated 911 operators while warning passersby of the danger and to “get out of here.”

Gunfire can be heard for at least 5 minutes and 30 seconds of the call.

Former CDC Director Susan Monarez confirmed at least four buildings at the public health agency were struck. Photos showed numerous bullet holes in the windows.

The shooter, identified by the GBI as Patrick Joseph White, 30, of Kennesaw, was found dead on the second floor of the CVS building. He died from a self-inflicted gunshot wound, officials said.