A gunman in apparent 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. "It got to the point where we believed that (the firefighters') lives were in immediate danger," Gwinnett County 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 Ritter. All those involved in the incident -- including the Gwinnett County police officer -- were in good condition as they were treated at Gwinnett Medical Center, hospital spokeswoman Beth Okun said. Several have been released, she said. "They are simply relieved that the situation is over," said Gwinnett County Fire Department spokesman Thomas Rutledge. "The firefighters are glad to be getting treated ... and really work on getting their lives back to normal." The hostage situation began around 3:40 p.m. Wednesday when the firefighters went to a residence in Suwanee "for some type of medical call," Ritter said. Four hours later, he noted authorities still weren't sure whether that call was for a "fake heart attack" or the gunman was actually suffering from a medical condition. One fire engine and an ambulance were sent to the scene, as is customary, Rutledge said. He explained that the firefighters involved are cross-trained as paramedics so they can provide aid to county residents in purported medical emergencies like this, which happen "hundreds of times throughout the year." "This is what they do, it's what they do very well," said Rutledge, saying the firefighters had no reason to think this situation would turn violent. "This call seemed to be no different ... They were caught off guard."