The grandmother of a 5-year-old held hostage for a week in an underground bunker in rural Alabama said Tuesday the boy is OK physically, but she fears the ordeal could stay with him the rest of his life.

Betty Jean Ransbottom told The Associated Press the boy seemed fine in the hospital on Monday after his rescue, but the family isn't sure yet how he is doing mentally.

The boy was abducted from a school bus last week after 65-year-old Jimmy Lee Dykes shot the driver and took the child back to a bunker on his property. Authorities raided the shelter after determining Dykes had a gun, saying he appeared to be increasingly agitated and that negotiations had deteriorated.

Dykes was killed by law enforcement agents, an official told The Associated Press on condition of anonymity because the official wasn't authorized to speak publicly about the investigation.

Neighbours had described Dykes as a nuisance who once beat a dog to death with a lead pipe, threatened to shoot children for setting foot on his property and patrolled his yard at night with a flashlight and a firearm. A Vietnam War veteran, Dykes had some scrapes with the law in Florida, one involving a weapon and another marijuana.

Ransbottom said an FBI agent stayed with the family the entire time the boy was being held hostage, but officials are not giving the family much information because of the ongoing investigation. They learned of his rescue when an FBI agent at the scene called the agent staying with the family.

Ransbottom said she cried herself to sleep every night while the boy was being held hostage, and that she didn't sleep much while she awaited news.

"It was horrible. I never went through anything so horrible," she said.

Debra Cook, Ransbottom's sister, said the family was grateful for the community's prayers and support. Fliers around town asked people to pray for the boy, and others gathered at nightly vigils to pray for his safe return.

"He has gone through a terrible ordeal, and I don't know if he will ever get over it," Cook told the AP. "I just want him to be all right."

Earlier Tuesday, Cook had told ABC's "Good Morning America" that the boy was happy and playing with toys, including a dinosaur.

School officials said at a news conference Tuesday that they planned to have a party to celebrate the boy's birthday, which is Wednesday, though they had not yet set a date for the party. The celebration, likely at the high school football field, would also honour the memory of Charles Albert Poland Jr., the bus driver credited as a hero for his actions to keep nearly two dozen other children on the bus safe.

Principal Phillip Parker said his colleagues were eagerly awaiting the boy's return, though he did not know when that would be.

"We'd love to have him back tomorrow," he said.

Parker stands at the entrance to the school every day as the children arrive, and described the boy as a friendly, energetic child who comes up, shakes his hand and then continues on into the school as if he's in a hurry.

After FBI agents determined that talks with an increasingly agitated Dykes were breaking down, they stormed the shelter Monday afternoon and freed the child.

Dale County Coroner Woodrow Hilboldt said Tuesday that officials had not yet removed Dykes' body from the underground shelter. Hilboldt said he does not know how Dykes died because he has not yet examined the body. Hilboldt said the body will be taken to Montgomery for an autopsy, though he did not know exactly when that may happen.

Meanwhile, federal authorities were tight-lipped about specifics of how they ended the standoff.

Neighbours said they heard a bang and gunshots, but the FBI wouldn't confirm that. Authorities also kept under wraps exactly how they were able to monitor Dykes and the boy in such a confined space.

Dale County Sheriff Wally Olson said Dykes was armed when officers entered the bunker. He added the boy was threatened, but declined to elaborate.

It was not immediately clear how authorities determined the man had a gun.

The boy was reunited with his mother and taken to a hospital to be checked out. Officials have said he has Asperger's syndrome and attention deficit hyperactivity disorder.

While the normally tranquil town of 2,400 people anxiously waited for days, authorities had been speaking with Dykes though a plastic pipe that led into the bunker, which was built like the tornado shelters frequently found in the South.

Authorities sent food, medicine and other items into the bunker, which apparently had running water, heat and cable television but no toilet.

On Tuesday, FBI bomb technicians were to continue scouring the property for any explosive devices as officials prepared to collect evidence and more thoroughly study the site, said FBI special agent Jason Pack.

At the request of law enforcement authorities, Secretary of Defence Leon Panetta had approved the provision of certain equipment that could be employed to assist in the hostage situation, according to a U.S. official who requested anonymity to discuss a pending law enforcement matter. It is not clear whether the equipment was actually used.

Photo: Dale County Sheriff Wally Olsen answers questions from the media about the close of the hostage crisis during a news conference late Monday, Feb. 4, 2013, in Midland City, Ala. Authorities stormed an underground bunker Monday in Midland City, freeing the 5-year-old boy and leaving his captor dead after a week of fruitless negotiations that left authorities convinced the child was in imminent danger. (AP Photo/AL.com, Jay Hare)"