EDMONTON - Investigators have now determined that a wildfire that swept through the town of Slave Lake on May 15th was likely recklessly or deliberately set.

The government has now turned the investigation of the fire over to the RCMP.

"Our investigation into the origin of that fire ruled out everything but arson as a probable cause," Sustainable Resource Development (SRD) Minister Frank Oberle said in a written release. "As a result, we have delivered our findings to the RCMP to determine if a criminal investigation is the next step."

Officers from the RCMP "K" Division Serious Crimes Branch are reviewing the case and will determine the course of action for the investigation.

"The RCMP has a very keen understanding of the devastation caused by this fire," said Deputy Commissioner Dale McGowan, Commanding Officer "K" Division. "I want to reassure the citizens of Alberta that a thorough review of the SRD report is a matter of high priority for the RCMP."

All 7,000 residents of Slave Lake were forced to leave the town as a result of the fire. Approximately 400 structures, mostly homes, were destroyed.

No residents were injured, but a helicopter pilot who was involved in the fire fight died when his helicopter crashed into Lesser Slave Lake.

It took 1,400 firefighters and 170 helicopters and tankers to battle the blaze.

The 4,700-hectare fire that swept through the town was one of 45 fires that burned in the Lesser Slave Lake area between May 13th and 16th.

Damage from the Slave Lake fire is pegged at $700 million. Insurance adjusters believe it is Canada's second most expensive disaster, after the Quebec ice storm of 1998.

The damage from the fire was so extensive the event received worldwide media coverage.

In July, Prince William and his wife Kate made a brief stop in the town during their tour of Canada.

SRD's investigation of the fire took more than five months to complete, and the government believes the evidence was gathered according to internationally accepted standards for wildfire investigations.

"Our investigation took the time required to protect, collect, analyze and document evidence to the rigorous standards required for presentation in a court of law," Oberle said.

Approximately half of the 1,600 fires that occur in Alberta's Forest Protection Area (FPA) each year result from human actions, such as unattended campfires and slash burning.

The province provided nearly $300 million in aid following the fire. A portion of the funding was used to set up modular mobile housing units for displaced residents.

There are currently 223 mobile housing units in Slave Lake. Of those, 165 are occupied by families who lost their homes to the fire. The unoccupied mobile units still need work before residents can move in.

There are still 20 to 30 families who need a mobile housing unit to move into, although all families with school-aged children have been placed into a mobile residence.

On September 30th, a family was able to move into the first home built in the town since the devastating fire.

With files from Laurel Clark