(MIDLAND CITY, Ala.) -- Jimmy Lee Dykes, the man who held a young boy hostage for nearly a week in an underground bunker in Alabama, had two homemade explosive devices on his property and engaged in a firefight with SWAT agents before they stormed the bunker and killed him, according to the FBI.
One explosive device was found inside the bunker and another was located in the PVC pipe negotiators used to communicate with Dykes, the FBI said Tuesday night. Both devices were "disrupted," according to the FBI. The search for hazards is expected to continue through Wednesday.
Preliminary investigation reports indicate that Dykes engaged in a firefight with the SWAT agents who made entry on Monday, according to the FBI.
Officials were able to insert a high-tech camera into the 6-by-8-foot bunker to monitor Dykes' movements, and they became increasingly concerned that he might act out, a law enforcement source with direct knowledge of the case told ABC News on Monday.
FBI special agents were positioned near the entrance of the bunker and negotiators were able to convince Dykes to approach the bunker door. FBI agents used two explosions to gain entry into the bunker. It also appears that Dykes reinforced the bunker against any attempted entry by law enforcement, according to the FBI.
ABC News has learned that Dykes first opened fired on the agents during the bunker raid. Moments later, the agents returned fire, killing Dykes.
The shooting review team continues to gather facts regarding the incident, the FBI said.
The boy, only identified as Ethan, was rescued from the scene by a waiting ambulance. The bunker raid came six days after Dykes boarded a school bus, fatally shot the driver and abducted the boy, who suffered no physical injuries.
Meanwhile, Ethan is set to celebrate his sixth birthday on Wednesday, happily reunited with his family.
Ethan's relatives told ABC's Good Morning America on Tuesday that he seemed "normal as a child could be" after what he went through and has been happily playing with his toy dinosaur.
"He's happy to be home," Ethan's great uncle Berlin Enfinger told GMA. "He's very excited and he looks good."
In a statement released by the FBI on Tuesday, Ethan's mother said, "For the first time in almost a week, I woke up this morning to the most beautiful sight...my sweet boy. I can't describe how incredible it is to hold him again."
Ethan is "running around the hospital room, putting sticky notes on everyone that was in there, eating a turkey sandwich and watching SpongeBob," Dale County Schools Superintendent Donny Bynum said at a news conference on Tuesday.
When asked about a birthday party for Ethan, Bynum said, "We are still in the planning stages. Our time frame is that we are waiting for Ethan, waiting on that process, but we are going to have it at a school facility, most likely the football stadium at Dale County High School."
Copyright 2013 ABC News Radio