Man dies when large firework explodes in his hand atop abandoned Twin Cities building

A man died from injuries suffered when a large firework exploded in his hand over the Fourth of July weekend in the Twin Cities.

The Lake Johanna Fire Department says first responders were called around 1:30 a.m. Sunday to the rooftop of an abandoned building off County Road I on the former Twin Cities Army Ammunition Plant site in Shoreview, Minnesota.

The 911 caller said the victim, a man in his 20s, had "injuries to his face and chest" and "was unconscious but breathing."

The stairs were "not usable for rescue," said Fire Chief Tim Boehlke, so firefighters used an aerial platform to reach the victim. He was rushed to Hennepin Healthcare in Minneapolis where he later died.

Boehlke says investigators were later told the victim was on the roof with 15-20 people when the shell inside the mortar tube he was holding exploded. It's not clear if anyone else was hurt.

"Our deepest sympathies go out to the family and friends of this young man," Boehlke said.

Several agencies are assisting in the investigation, including the Ramsey County Sheriff's Office.

The U.S. Consumer Product Safety Commission says there were 15 reported firework-related deaths and around 13,000 injuries last year. 

Experts say to keep a bucket of water or a hose close by in case there's a problem, and never relight or pick up fireworks that haven't fully ignited.