A national team of fire specialists arrived at the burnt remains of the Press Bar and Parlor in St. Cloud on Friday to begin investigating the source of the blaze and whether arson may have been a factor.

The fire erupted early Monday, leaving the 100-year-old two-story downtown building a total loss, with damage estimates exceeding $1 million.

The National Response Team, part of the Bureau of Alcohol, Tobacco, Firearms and Explosives, will join local fire departments and Minnesota-based ATF agents in reconstructing the scene of the fire, identifying the location of origin, conducting interviews and sorting through rubble.

"ATF's involvement in this investigation is strictly as a support role," Special Agent in Charge William Terry Henderson of the St. Paul Field Division said in a statement. "This was a large fire and the extra personnel will help move this investigation along more quickly."

The last time the local ATF field office summoned a National Response Team was in 2004. The teams have also been deployed to high-profile events such as the Oklahoma City federal building bombing, the Pentagon crash site on Sept. 11, 2001, an explosion in West Texas and blasts at explosives and ammunition manufacturing plants and fireworks factories, according to the ATF.

ATF spokeswoman Ashlee Sherrill said it's too early to say whether investigators suspect foul play. "The whole purpose is to discover the origin and cause, which we can't know going into it," she said.

The ATF established the National Response Teams in 1978 to assist on "scenes of significant explosions and arson incidents."

The response teams consist of forensic chemists, explosives enforcement officers and other veteran special agents from across the country with experience in "post-blast" and fire-origin expertise.

The ATF is also bringing in a dog trained to sniff out accelerants, such as gasoline, in the rubble. It is the sixth NRT activation of the fiscal year and the 853rd since its inception.

The last time the team was in Minnesota was in January 2004 at the Metro Club Building in St. Paul.

About 30 ATF agents are now involved in the investigation, working alongside the St. Cloud Fire Department, the St. Cloud Police Department and the State Fire Marshal's Office.

Members from the teams come from all over the country and usually arrive within 24 hours of being called. Their investigation will result in a road closure in the 10 block of 5th Avenue S., with limited pedestrian traffic on the south end of the block, St. Cloud Fire Chief Dean Wrobbel said in the statement.

Fire crews responded to the Press Bar, at 502 W. St. Germain St., around 2:40 a.m. Monday. It took about 40 crew members to extinguish the fire.

"Our thoughts and prayers are with the brave dedicated firefighters who have been fighting the fire at the Press Bar since early this morning," St. Cloud Mayor Dave Kleis said in a tweet.

No one was injured, but part of the building collapsed. Fire officials said the structure was a total loss.

The Press Bar, opened in 1942, was long a staple of the St. Cloud dive bar scene.

"We are thankful that no one was in the building at the time of the fire," said a statement from the bar.

"We've gained many great employees, friends and memories there over the years."