A team from the Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF) arrived in St. Paul on Thursday to help local officials determine what sparked a fire that destroyed a Marriott hotel and apartment complex that was under construction.

The early Tuesday blaze broke out at the site of the $69 million Seven Corners Gateway project on W. 7th Street across from the Xcel Energy Center in downtown St. Paul and sent flames and smoke shooting high into the air that could be seen from miles away.

The St. Paul Fire Department requested the help from the ATF's National Response Team because of the large amount of damage, the intensity of the fire, and the number of investigative agencies involved.

"The extra personnel will help move this investigation along more quickly," said Special Agent in Charge Terry Henderson of the ATF's St. Paul Field Division.

This is the fifth time the National Response Team has been in Minnesota this year. The team supported more than 150 arson investigations in the Twin Cities after a period of unrest earlier this summer following the death of George Floyd, the Black man who was killed while being detained by Minneapolis police.

The team also helped investigate the Press Bar and Parlor fire in January in St. Cloud and was in Grand Rapids in February to investigate a fire at a behavioral health clinic.

Until this year, the special ATF team had not been in Minnesota since 2004.

The National Response Team is composed of agents who have expertise in determining origins and causes of fires and explosions. Team members include forensic chemists, explosives enforcement officers, fire protection engineers, computer forensic specialists, accelerant-detection canines and explosives-detection canines.

AFT established the response teams in 1978 and have responded to scenes such as the 1993 World Trade Center bombing, the 1995 Oklahoma City federal building bombing and the Sept. 11, 2001, Pentagon crash site.

Carl Kaeding, president of Bloomington-based Kaeding Development Group, said he plans to restart the project that includes a five-story 120-room Courtyard by Marriott hotel and a six-story building with 144 market-rate apartments.

"Our intent is to continue," he said earlier this week.