The fire happened last week at a construction site across the street from the Xcel Energy Center.
The man is accused of helping his brother and sister-in-law avoid arrest.
The ATF says it's a 'potential explosive device.'
Each of the 14 suspects carries a $5,000 reward.
Rewards totaling $10,000 are being offered to find them.
They are wanted for questioning over a series of fires in Minneapolis.
The St. Paul ATF is offering $5,000 for information leading to his arrest
They're wanted for questioning in connection with arsons in St. Paul.
The ATF is assisting St. Paul PD with its investigations.