Midland City, Alabama (CNN) -- A 5-year-old boy freed Monday after being held captive in an underground bunker for six days is laughing and smiling and playing with his favorite toy dinosaur after being reunited with his family, authorities said.
The boy's kidnapper is dead, but officials offered no details on the raid that freed the boy -- identified only by his first name, Ethan -- and left his abductor fatally shot.
FBI Special Agent in Charge Steve Richardson visited Ethan at a hospital, where he was in a private area with heavy security.
"He is doing fine," Richardson told reporters at a late-night news conference. "He's laughing, joking, playing, eating."
Dale County Sheriff Wally Olson had no new details about Ethan's rescue, and when asked if the boy saw his abductor, 65-year-old Jimmy Lee Dykes, killed during the rescue operation, Olson replied, "He's a very special child. He's been through a lot, he's endured a lot."
Ethan looks great but will be hospitalized overnight, an uncle told people at a prayer vigil earlier Monday.
Authorities said they were still working on the crime scene and the investigation should continue for several more days. The sheriff's office said the bomb squad was checking the bunker for potential explosive devices.
Richardson earlier said an FBI team went in to get Ethan after negotiations had broken down with Dykes, who also was "observed holding a gun."
Olson said it became very difficult to deal with and even communicate with Dykes over the past day.
Believing the child to be in imminent danger, an FBI team entered the bunker at 3:12 p.m. CT (4:12 p.m. ET) and rescued the boy, Richardson said.
One neighbor said he was outside when he was startled by the sound of an explosion.
"I heard a big boom and then ... I believe I heard rifle shots," said Bryon Martin, who owns a home near the bunker where the boy had been held since Tuesday.
It was a loud noise that "made me jump off the ground," he said.
Authorities wouldn't say whether the blast was set off as a diversionary tactic or whether Dykes had planted explosives around the bunker.
After the good news of the boy's release spread through the small rural community, travelers on a nearby highway honked their horns as they drove by.
The FBI had borrowed from the U.S. military high-tech detection equipment similar to the technology used to discover homemade bombs in war zones, three Defense Department officials told CNN.
It was unclear whether the equipment, which is not readily available to civilian law enforcement, had been used by the FBI.
One of the defense officials said no members of the military were involved in the rescue. They would have been acting a technical advisers, the official said.
Last Tuesday, police said, Dykes boarded a Dale County school bus and demanded the driver hand over two children.
The driver, Charles Albert Poland Jr., refused, blocking access to the bus's narrow aisle as at least 21 children escaped out of the back emergency door, authorities said.
The gunman killed Poland, then grabbed a kindergartner before barricading himself and the boy inside a nearby bunker he had built.
Smith said Monday that Ethan has siblings, but none of them were on the bus last week.
In the ensuing days, officials said little about what was going on in the bunker or in their strategy, or what -- if anything -- Dykes wanted.
"Based on our discussions with Mr. Dykes, he feels like he has a story that's important to him, although it's very complex," Olson said Monday before the hostage situation ended. He didn't elaborate.
Ethan suffers from Asperger's syndrome and attention deficit disorder, state Rep. Steve Clouse said during the week.
Dykes told authorities that he had blankets and a heater in the bunker, and authorities have previously said the bunker -- built 4 feet underground -- has electricity.
Authorities did not say how they were communicating with Dykes.
Meanwhile, residents and business owners in Midland City put up blue, red and black ribbons in support of the boy and Poland. Blue and red are the local school colors, and black is in honor of the slain bus driver.
The U.S. Navy confirmed Monday that Dykes served in the military from 1964 to 1969.
Naval records list him as an aviation maintenance administrationman third-class who served with units based in California and Atsugi, Japan. The job entails clerical work related to aircraft and aircraft maintenance, according to the Navy's job description.
Neighbors and officials had described Dykes as a survivalist with "anti-government" views.
Even as the hostage situation continued Monday morning, plenty of police were on hand as schools in neighboring Ozark, Alabama, reopened for the first time since the incident began.
Dale County schools remained closed but were to reopen on Tuesday, the district said.
In Ozark, school officials decided to begin strictly enforcing a 15-foot safety zone around school buses required by state law. The law prohibits any unauthorized adults, including parents, from approaching within 15 feet of a school bus stop. If an unauthorized adult gets too close, bus drivers are supposed to close bus doors or drive away, if necessary, school officials said
CNN's Victor Blackwell and Martin Savidge reported from Midland City; Barbara Starr contributed from Washington; Michael Pearson and Steve Almasy reported and wrote from Atlanta; and CNN's Vivian Kuo and Larry Shaughnessy also contributed to this report.