SUWANEE, Georgia (CNN) -- A gunman who apparently was in financial distress took several firefighters hostage Wednesday in suburban Atlanta, then was killed in an exchange of gunfire hours later after law enforcement authorities determined he might lash out at his captives at any time.
"It got to the point where we believed that (the firefighters') lives were in immediate danger," Gwinnett County, Georgia, police spokesman Ed Ritter said Wednesday night. "And our SWAT team made the decision to go in there and neutralize the situation."
All four Gwinnett County firefighters who were being held hostage suffered "superficial" injuries after authorities used explosives "to distract the suspect to get in the house and take care of business," Ritter explained. Their injuries were the result of the explosions, not gunfire, and all four were expected to go home by night's end.
One law enforcement officer was shot in the incident, but his injury is not considered life-threatening, according to the police spokesman.
The hostage situation began around 3:40 p.m. Wednesday when the firefighters went to a residence in Suwanee, Georgia, "for some type of medical call," Ritter said. Four hours later, he noted that authorities still weren't sure whether that call was for a "fake heart attack" or the gunman was actually suffering from a medical condition.
Gwinnett County Fire Department spokesman Thomas Rutledge later said one fire engine and an ambulance were sent to the scene, as is customary. He explained that the firefighters involved are cross-trained as paramedics so they can provide aid in cases like this, which they believed was "a typical medical emergency at a private residence."
"There was no indication or any reason to believe that there would be a violent situation," Rutledge said.
Neighbors said five firefighters had gone inside the home -- a two-story structure, one of many in the neighborhood about 30 miles northeast of Atlanta -- with a stretcher, then the single firefighter ran out about 30 minutes later. Rutledge, the fire department spokesman, later explained that one firefighter was released so he could move the fire truck from in front of the house
The house was foreclosed upon in November and was being prepared for sale, said Brad German, a spokesman for Freddie Mac. It was not clear what, if anything, that fact had to do with what unfolded Wednesday.
Ritter, the police spokesman, did say that the gunman started making demands related to the house after taking the firefighters hostage.
"The power was turned off along with the cable and cell phone and so on, and he wanted all those things turned back on," said Ritter, adding that "apparently he was going through some financial issues."
Hostage negotiators were on site, as were agents from the federal Bureau of Alcohol, Tobacco, Firearms and Explosives, according to Richard Coes, a spokesman for that agency.
Explosions were heard around 7:30 p.m., and soon after ambulances were seen leaving the scene.
Ritter explained a short time later that there had been an exchange of "gunfire between officers and that individual."
"This was his call, his decision, this was the result of his actions," the police spokesman said.
"We didn't want it this way. But he was calling the shots."