An Alabama boy is set for the "greatest" birthday of his life after being freed from a week's captivity in an underground bunker, a pastor said Tuesday.

The boy, snatched from a school bus in a fatal shooting, was rescued after a daring raid by FBI agents that left his kidnapper, Jimmy Lee Dykes, dead.

The 5-year-old, who is recovering in hospital, turns 6 on Wednesday. 

“I would image it’s going to be the greatest birthday that family and that little boy has ever experienced and probably will ever experience,” local pastor Michael Senn told TODAY.

The boy was reunited with his mother and is "laughing, joking, playing, eating," said Special Agent in Charge Stephen Richardson at a press briefing Monday.

"He's very brave, he's very lucky. His success story is that he got out and he's doing great."

Richardson said the operation began when Dykes was seen holding a gun. "At this point, FBI agents, fearing the child was in imminent danger, entered the bunker and rescued the child.” 

The Dothan Eagle newspaper reported that two loud blasts came from the scene shortly before 3:30 p.m. According to the report, an ambulance then drove up the private dirt road where Dykes’ homes is located and then left a short time later.

The blast apparently came from a "diversionary device," an FBI source confirmed to NBC News. FBI officers had lowered a camera into the bunker -- they would not reveal how, saying they may want to use the method in the future -- which allowed them to determine when to throw in the flash-bang to distract Dykes.That's when they entered through a door at the top of the bunker. 

At the Monday night press briefing, Dale County Sheriff Wally Olson said that Dykes, 65, was harmed when officers entered the bunker but he would not say how the captor died. A law enforcement official told NBC News they are waiting for the medical examiner's report to determine how he died.

Related: Official says boy is his 'lovely' self after rescue

The ordeal began at 3:30 p.m. CT last Tuesday when Dykes -- described by his neighbors as a paranoid survivalist -- grabbed the boy from a school bus in Midland City, Ala.

Dykes boarded the bus and demanded that the bus driver, Charles Poland, 66, turn over two young children. When Poland refused, Dykes fatally shot him and took the boy.

Dykes, a decorated Vietnam veteran, took Ethan to an underground bunker that neighbors had seen him digging. The bunker is believed to be roughly 8 feet by 6 feet and to be stocked with supplies. The bunker has a ventilation pipe that authorities used to deliver items. Authorities have not said how long they believe Dykes could have lasted underground, or discussed a motive for the kidnapping.

Over the last week, hostage negotiators delivered a red Hot Wheels car, Cheez-Its crackers and other food and medicine to the boy, who has a mild form of autism. The FBI said Sunday that the boy’s captor “continues to make the environment as comfortable as possible for the child.”

The boy has Asperger’s syndrome and attention deficit hyperactivity disorder, a state representative said last week.

Law enforcement officials remained largely mum about the details of the case, possibly because it was believed that Dykes kept a television set in the bunker. Early on in the negotiations, they moved reporters farther from the scene. Throughout the week, they canceled press conferences, saying that nothing had changed.

Many of the law enforcement press conferences appeared to have been directed more at Dykes than at reporters. Sheriff Olson went so far as to thank Dykes “for taking care of our child.”

“That’s very important,” Olson said.

Before the standoff ended on Monday, Olson told reporters that Dykes "feels like he has a story that’s important to him. ... Although it’s very complex, we’re trying to make a safe environment.”

At the Monday night press briefing, Olson would not say what that story was, repeating that the investigation was ongoing and that the crime scene still needed to be processed. But he was passionate -- and willing to discuss -- Ethan.

"This boy is a very special child. He's been through and endured a lot and by the grace of God, he's OK," Olson said. "That was the mission of every man and woman on this compound. Of every law enforcement officer, every first responder, and all of the community who prayed to bring him home safely." 

Former FBI hostage negotiator Clint Van Zandt said on the TODAY show that patience is key in hostage situations.

“Eighty-five percent or more of standoff situations like this end nonviolently,” Van Zandt said on Saturday. “Law enforcement doesn’t want to do anything precipitously that could cause anybody to be hurt at this time when the talking cure will likely work in this situation.”

Following the end of the hostage situation, Alabama Gov. Robert J. Bentley released a statement, hailing the efforts to save the boy but mourning the death of the bus driver:

"I am thankful that the child who was abducted is now safe. I am so happy this little boy can now be reunited with his family and friends. We will all continue to pray for the little boy and his family as they recover from the trauma of the last several days."

President Barack Obama also weighed in, calling FBI Director Robert Mueller to compliment his officers. 

NBC's Gabe Gutierrez, Erin McClam, Matthew DeLuca, Jeff Black and Pete Williams contributed reporting. 

Related:

Son says bus driver in Alabama hostage crisis gave life for 'his children'

Sheriff to Alabama hostage-taker: 'I want to thank him for taking care of our child'

A military veteran who was severely injured in a parade crash in Texas last week recalled chilling screams before an oncoming train plowed into the flatbed truck he was riding, killing four people and injuring others.

Sgt. 1st Class Richard Sanchez, who broke his back in the crash and could be paralyzed, spoke with Matt Lauer from his hospital bed on TODAY Monday about the moments before impact. He was on the second truck in the annual Show of Support parade for military veterans in Midland, Texas, that was hit by a Union Pacific freight train as it crossed the tracks.

“It all kind of happens at once, there’s not really any delay in time, but I remember it all from the first time I heard somebody yelling ‘train!’ to the arm coming down on my wife and I, and then me pushing her and me getting thrown,’’ Sanchez said. “It just all seems to go by extremely fast. My wife and I were kind of already almost past the train tracks, so we were already looking off to start waving to the next group of little kids, but one of the ladies behind us… yelled ‘train!’ And I just happened to look up and saw the crossing arms come down.’’

In a timeline created by the National Transportation Safety Board from information in the train’s black box along with video from the train and a sheriff’s escort car, the warning bells and lights for the train crossing began going off 20 seconds before the impact. Thirteen seconds before the crash, the crossing gates started to come down after the first truckload of veterans crossed the tracks.

With 12 seconds before the crash, the second truck began to cross the tracks. The engineer sounded the train’s horn and then slammed on the emergency brake five seconds before impact, but it was too late.

“I remember the guard coming down, I remember Richard yelling at me to jump, and I remember his hands on my back,’’ Sanchez’s wife, Heather, told Lauer. “The next thing I know I was on the ground, and I saw my husband laying in a ball. I thought he was dead. He wasn’t moving, it didn’t look like he was breathing, (and) there was blood everywhere. He was just crumpled up, so I just started screaming his name, and that’s when he woke up.’’

“I had my back broken down by the L5 (veterbra),’’ Richard said. “I’m just kind of waiting to see if we can get the swelling down by the spinal cord so I can try to walk again.’’

The veterans from the first truck that made it safely across the tracks quickly raced back to help those injured in the crash.

“For many of them, their training kicked in, and as soon as they jumped off that trailer they were able to help tie tourniquets and stop bleeding vessels,’’ Dr. Sudip Bose, a military physician who treated those injured on the scene, told NBC News. “I couldn’t have done it without their help.’’

The NTSB has not publicly identified the driver and plans to interview him on Monday. He did submit a blood sample immediately after the accident. On Tuesday, the NTSB will have a re-enactment of the crash in order to better determine why it occurred.

Sanchez, who had just returned from a deployment in Afghanistan before the parade, plans to pursue legal action for his injuries. Sanchez’s attorney, Bob Pottroff, spoke with Lauer alongside the Sanchezes.

“You start out by knowing that you don’t hold anybody who was on that float responsible,’’ Pottroff said. “This should never have happened, so you kind of look backwards. There’s reasons why this happened.

“One of the reasons is obvious. The 20-second warning time is not a sufficient warning. You only have to go back to Fox River Grove in Illinois in 1995 to know what happens when you have a short warning time. In that instance, a busload of children were hit. The same warning time in this case, and that is not the way that system was designed. I know it was designed for a 30-second warning time. That information is what we hope to bring to light.”

Read more:

Wounded vet dies saving wife on parade float in Texas train accident

Land I love: Why you're proud to be Americans

Lauren Scruggs: I felt like something was going to happen on night of accident