The FBI and police sought to get as much information as they could gather on Dykes.
Neighbors told them that Dykes is known as "Mean Man" because of his anti-government rants, and for carrying a rifle and a shovel. A decorated Navy veteran, Dykes was due in court that very day to face charges of shooting at one of his neighbors.
As for the bunker, Dykes had painstakingly built it himself and had shown it off to neighbors. But no one knew its secret purpose until the standoff.
The bunker was 12 feet deep, and about eight feet long by six feet wide. Dykes fitted it out with electricity, a TV, bunk beds, food, water and other living essentials.
There was a PVC pipe poking up above ground from the bunker, and Dykes told police they could speak to him through the pipe.
Police quickly discovered that Dykes has built in some deadly surprises. There was a bomb in the pipe.
"Well, he had the knowledge and the sophistication to build a device that could not only kill himself and the little boy, but could kill us as first responders and bomb technicians," FBI bomb tech Al Mattox said.
That gave law enforcement some grudging respect for Dykes' abilities, and also raised some disturbing questions.
ABC News asked Sheriff Olson about the possibility of additional, hidden bombs on Dykes' property.
"Absolutely," Olson said. "I mean, if you got one IED here, you don't know what lies out there waiting for you.
The law enforcement team felt the best chance of saving Ethan would be negotiating with Dykes.
FBI behavioral scientist Molly Amman was flown down to Alabama to help with the unfolding crisis. She quickly assessed the situation and said it did not look good.
"I was immediately concerned," Amman said. "He [Dykes] was angry but intelligent and controlled."
She knew she was dealing with a cold-blooded killer.
"Charles Poland was a friend of his. Maybe his only friend," Amman said. "He very coldly made a promise ... to Mr. Poland: 'You will do this or I will kill you.' And he killed him."
Amman said they were dealing with a kidnapper who lacked "empathy, remorse, regret."
The hostage team, led by top negotiator Sean Van Slyke, quickly tried to soothe Dykes in direct talks on the phone.
"We wanted to try to come in and calm the situation down, try to calm down his emotions and really just try to stabilize what is a very volatile situation," Van Slyke said.
"It was complex and detailed and nuanced, and every minute of every hour of every day the complexities grew," Amman said. "We didn't know how he was going to react. We didn't know how Ethan was going to react."
The negotiating team wouldn't say how they knew, but they somehow did know that Dykes was watching TV in that bunker. So they carefully tailored their message to protect Ethan when addressing the cameras, with Sheriff Olson saying: "I want to thank Mr. Dykes for taking care of Ethan."
The strategy seemed to work. Ethan remained calm in the bunker, playing with coloring books and toy cars sent down to keep him occupied.
Meanwhile back in town, the bus driver, Poland, was buried and a community grieved. He was a hero to the community, but to his wife, so much more.
"He was my best friend, my sweetheart," she said through tears. And she wasn't surprised he stood up for the children on his bus. "He loved those kids."