Until Wednesday, the railway had defended its employees' actions, but that changed abruptly as Burkhardt singled out the engineer as culpable.
"We think he applied some hand brakes, but the question is, did he apply enough of them?" Burkhardt said. "He said he applied 11 hand brakes. We think that's not true. Initially we believed him, but now we don't."
He said the engineer was "under police control."
"He's not in jail, but police have talked about prosecuting him," the CEO said. "I understand exactly why the police are considering criminal charges ... If that's the case, let the chips fall where they may."
Burkhardt did not name the engineer during his impromptu and sometimes chaotic outdoor news conference, though the company had previously identified the employee as Tom Harding of Quebec and termed him a hero for rushing to the scene and managing to stop some of the Montreal, Maine & Atlantic Railway train's runaway cars. All but one of the 73 cars was carrying oil, and at least five exploded.
Burkhardt, who arrived in town with a police escort, said he had delayed his post-crash visit to Lac-Megantic in order to deal with the crisis from his office in Chicago, saying he was better able to communicate from there with insurers and officials in different places during what he described as 20-hour work days.
"I understand the extreme anger," he said, likening the devastation in Lac-Megantic to a war zone. "We owe an abject apology to the people in this town."
He pledged that his company which will likely face lawsuits would work with local officials, relief groups and others to help the community recover.
After the wrecked cars are cleared away, Burkhardt said the railway would repair the tracks and resume train operations.
Asked if he would build those tracks on the perimeter of the town instead of through it again, he said that was under consideration as a long-term plan.
In an exchange with reporters, Burkhardt defended the practice of leaving trains unmanned, as was the case when the runaway began.
"I don't think it was wrong, but you always look at any accident and you say, 'How could we have done better?' " he said. "And for the future we, and I think probably the rest of the industry, aren't going to be leaving these trains unmanned. We'll take the lead with that. I think the rest of the industry is going to follow."
Among the residents looking on as Burkhardt spoke was Raymond Lafontaine, a prominent local businessman who is believed to have lost a son, two daughters-in-law and an employee in the disaster.
"That man, I feel pity for him," Lafontaine said. "Maybe some who know him properly may think he's the greatest guy in the world, but with his actions, the wait that took place, it doesn't look good."
"If he had come with some people who speak French, if a team had come to see us and, 'Yes, we're here for you and there was an accident, yes, there was human error, yes, this happened,' it seems like that would have hurt less," Lafontaine added. "I would have been able to get through that. But this is inconceivable. I can't accept it."
At a news conference shortly before Burkhardt's arrival in Lac-Megantic, Quebec Premier Pauline Marois also faulted the company's response to the disaster.
She depicted Burkhardt's attitude as "deplorable" and "unacceptable."
"I understand he doesn't speak French but he could have come," she said.
Well before Burkhardt's comments, Quebec police had said they were pursuing a wide-ranging criminal investigation.
The disaster forced about 2,000 of the town's 6,000 residents from their homes, but most have been allowed to return.