(Rewrites with 9/11 expert assisting with investigation)
By Phil Wahba
LAC-MEGANTIC, Quebec, July 17 (Reuters) - A U.S. expert who worked on the aftermath of the Sept. 11 attacks is helping Canadian authorities sift through wreckage left more than a week after a runaway train barreled into a lakeside town in Quebec killing 50 people, police said on Wednesday.
Frank DePaolo, an emergency specialist from New York's Office of the Chief Medical Examiner, visited the ruins of Lac-Megantic earlier in the week.
DePaolo is an expert in managing major disaster sites and is responsible for one of the forensic teams working at the collapsed World Trade Center towers in New York City.
"He said the efforts were complex and difficult and he was overwhelmed (by) the enormity of the situation," Quebec police spokesman Michel Forget told reporters.
A spokeswoman in DePaolo's New York office said he was not available for comment.
Investigators are painstakingly working their way through Lac-Megantic, where a runaway crude oil train derailed and exploded on July 6 leaving burned-down buildings, mountains of rail-related debris and charred trees. Some 37 bodies have been recovered and investigators are still searching for more remains.
It was North America's deadliest rail accident in more than 20 years.
The center of the town - in the mainly French-speaking province of Quebec - is considered a crime scene and it will likely be weeks to months before trains are able to run again.
Quebec police have said their investigation of the crash is still in its early stages, although they say they are looking at the possibility of criminal negligence.
Canada's new transportation minister, Lisa Raitt, met local officials in Lac-Megantic on Wednesday and said the federal government was ready to help the community. She gave no details.
Earlier on the day the railway company at the center of the disaster confirmed it had laid off a number of people in Maine and Quebec.
The cutbacks at the Montreal, Maine and Atlantic Railway (MMA) come 11 days after a runaway train hauling 72 tanker cars of crude oil derailed and exploded in the center of Lac-Megantic, leveling the heart of the small town.
"This is because of the track being broken at Lac-Megantic," Cathy Aldana, a vice president at Rail World Inc, the parent company of MMA, told Reuters. "The intent is to rehire the employees when the line is open again."
Aldana could not confirm how many employees were affected by the layoffs, but Canadian media outlets, citing union sources, reported that 19 people were laid off in Quebec alone.
A Quebec union representative was not immediately available for comment.
The disaster in Lac-Megantic has cut off local firms that use the railroad to ship their products to customers, including exports to Maine, just 18 miles (29 km) away. (Reporting by Phil Wahba in Lac-Megantic and Julie Gordon in Toronto; Writing by David Ljunggren; Editing by Vicki Allen and Lisa Shumaker)