DULUTH -- The Bureau of Alcohol, Tobacco, Firearms and Explosives has deployed a top national investigative unit to the scene of a fire that destroyed the Lakeview Behavioral Health and VFW Post 1720 buildings in downtown Grand Rapids.

The ATF's National Response Team arrived on site Tuesday, March 10, to join local and state investigators in the probe of the origin and cause of the Saturday night blaze. Their assistance was requested by the Grand Rapids Fire Department and Minnesota State Fire Marshal's Office.

“ATF’s National Response Team brings a wealth of knowledge and resources, to assist local fire departments during investigations of large structure fires such as this,” William Terry Henderson, special agent in charge of the ATF's St. Paul Field Division, said in a statement. “Nearly 25 ATF national response team members are activated for this investigation in addition to our local team of special agents who normally cover Minnesota and the surrounding states."

Smoke was reported at the Lakeview building, 20 NW Third St., shortly before 9 p.m. Saturday, March 7, and a fire quickly spread next door to the VFW. Crews from a number of fire departments worked the scene well into Sunday, but both buildings were deemed total losses.

The ATF's National Response Team consists of veteran special agents who have post-blast and fire-origin-and-cause expertise, forensic chemists, explosives enforcement officers, fire protection engineers, accelerant-detection canines, explosives detection canines, intelligence support, computer forensic support and audit support.

Established in 1978, there are three NRTs stationed across the U.S. to respond with on-site investigations at no cost to local or state authorities. But few fire investigations lead to their presence; the unit has averaged about 20 deployments nationwide each year since its formation.

The team has notably been called to assist in major investigations including the 1993 World Trade Center bombing; 1995 Oklahoma City federal building bombing; Sept. 11, 2001, Pentagon crash site; and 2013 Texas fertilizer plant explosion, as well as blasts at explosives and ammunition manufacturing plants, legal fireworks factories and illegal explosive-device manufacturing operations.

The team recently was deployed to the site of the Press Bar fire in St. Cloud, which resulted in the arrest of the business' owner on arson charges. Before that, the team had not been deployed to Minnesota since 2004.

“The extra personnel will help move this investigation along more quickly,” Henderson said of the Grand Rapids case. “Our goal here is to assist in a full investigation of this fire scene alongside our state and local partners, bringing it to a successful conclusion.”