CHICAGO (CBS) — Today marks the 15th anniversary of the E2 nightclub stampede that killed nearly two dozen people.

21 patrons perished at the former club located at 2300 South Michigan.

More than 50 others were hurt.

The stampede happened after a security guard used pepper spray to break up a fight.

Some people were trampled to death and others were trapped in the club’s stairway as they tried to escape the fumes.