BUFFALO, N.Y. (AP) —; A remorseless Timothy McVeigh calls the children killed in the Oklahoma City bombing "collateral damage," regretting only that their deaths detracted from his bid to avenge Waco and Ruby Ridge, according to a new book.

The book represents the first time McVeigh has publicly and explicitly admitted to the crime and given his reasons for the attack.

"I understand what they felt in Oklahoma City. I have no sympathy for them," McVeigh told the authors of "American Terrorist: Timothy McVeigh and the Oklahoma City Bombing."

McVeigh told Lou Michel and Dan Herbeck, reporters for The Buffalo News, he did not know there was a day care center inside the Alfred P. Murrah Federal Building, the authors said on Thursday's broadcast of "PrimeTime Thursday."

"I recognized beforehand that someone might be ... bringing their kid to work," McVeigh said, according to the ABC broadcast. "However, if I had known there was an entire day care center, it might have given me pause to switch targets. That's a large amount of collateral damage."

Michel said McVeigh's only regret was that the children's deaths proved to be a public relations nightmare that undercut his cause.

Still, McVeigh said he was disappointed when part of the building remained standing after his 7,000-pound bomb went off. "Damn, I didn't knock the building down. I didn't take it down," he said.

The April 19, 1995, bombing killed 168 people, 19 of them children. McVeigh, 32, is scheduled to be executed May 16.

McVeigh said he was the sole architect of the plan, resorting to threats against Terry Nichols' family when his Army buddy hesitated before helping to load the explosives into the rental truck.

In 75 hours of prison interviews with the Buffalo reporters, McVeigh, who was raised in Pendleton, outside Buffalo, got choked up while talking about killing a gopher in a field, but never expressed remorse for the bombing.

However, he had been brought to tears two years earlier while watching the disaster at the Branch Davidian compound near Waco, Texas. He was in the living room of Nichols' Michigan home when the compound burned to the ground during an assault by federal agents, killing about 80 members of the cult.

The model soldier had left the Army disillusioned, unable to live with the thought that he was an ally of "the biggest bully in the world, the U.S. government," according to Herbeck. Then when Congress banned certain assault weapons, "I snapped," McVeigh said.

Before deciding to bomb the Murrah building, McVeigh considered a number of different possibilities, including assassinating elected officials, Michel said.

The federal building, McVeigh decided, had everything he wanted: federal agents and glass in the front, making it vulnerable and giving TV cameras a good shot.

The morning of the bombing, like a soldier, he had cold spaghetti for breakfast. "Meals ready to eat ... are meant for high intensity. I knew I was going through a firestorm and I would need the energy," the Gulf War veteran said.

McVeigh, two blocks away when the bomb exploded, was lifted off the ground by the force of the blast. As he fled, he called to mind the song "Dirty for Dirty" by the group Bad Company. "What the U.S. government did at Waco and Ruby Ridge was dirty. And I gave dirty back to them at Oklahoma City," he said.

In 1992 at Ruby Ridge, Idaho, the wife and son of white separatist Randy Weaver were killed by federal agents during a standoff.

McVeigh told the authors he knew he would get caught and even anticipated execution as a form of "state-assisted suicide." Yet he worried initially about snipers as he was being charged.

"He was ready to die but not at that moment — he wanted to make sure that his full message got out first," Herbeck said.

The authors also talk of McVeigh's regrets over not having a family, saying he has thought about smuggling sperm out of prison. Overall, he has found prison bearable. "I lay in bed all day and watch cable television. ... I don't pay the electrical bill or the cable bill," he said.

McVeigh dismisses those who believe foreign terrorists or domestic militias helped him with the bombing. "The truth is, I blew up the Murrah building," he said, "and isn't it kind of scary that one man could reap this kind of hell?"