(Sid Hastings/AP Photo)

One person was killed and at least 20 others were injured this afternoon when fierce winds lifted a tent covering an outdoor beer garden in St. Louis, Mo., sending metal poles and chairs flying before it collapsed.

At least 100 people were in a beer garden set up next to Kilroy's Sports Bar in downtown St. Louis when the tent collapsed.  Seventeen people were taken to the hospital, including the man who died. Five of those were in critical condition.  At least 11 others arrived at the hospital as walk-ins.

"We transported seventeen people at this time. We have one confirmed fatality right now," St. Louis Fire Department Chief  David Jenkerson said. "We have five that we've transported that we consider critical."

Officials said they believe the man who died suffered a heart attack.

The collapse was caused when 50 mph wind gusts lifted up the tent, sending metal poles up in the air.

"It picked the tents up and started ripping them off their moorings," Jenkerson said.

"I thought a train fell off the track," Art Randall, owner of Kilroy's, told the St. Louis Post-Dispatch. "We all ducked for cover. Everything was going sideways. I had metal chairs ripping across the beer garden."

Kilroy's Bar, which is popular with St. Louis Cardinals fans, is located in downtown St. Louis near Busch Stadium, where the Cardinals had just won a baseball game against the Milwaukee Brewers.