"Our firefighters responded to a call they respond to hundreds of times, and that's a medical emergency," Rutledge said.
Two ambulances could be seen leaving after the gunfire ended.
Asked what kind of weapon or weapons the suspect had, Ritter said he didn't immediately know. He said investigators were in the house where the suspect's body remained.
A spokeswoman for Gwinnett Medical Center said Wednesday night that five firefighters and a wounded police officer were treated at the hospital and all were in good condition.
This was the second time in recent months that firefighters have been targeted.
On Dec. 24, a man in upstate New York set his house ablaze and shot and killed two firefighters as they arrived, then himself. Two other firefighters and a police officer were wounded.