Transcript for Colorado Motorcycle Show Erupts in Gunfire
debate next Saturday night at 8:00 eastern. Shooting and stabbing at a Colorado motorcycle show. This morning, at least one person is dead. Another half dozen are wounded. Police believe that a fight between rival biker gangs triggered this violence. Clayton Sandell son to scene in Denver. Reporter: The Denver expo that brought out more than 10,000 hard-core motorcycle fans turned violent just before 1:00 P.M. At the national western complex, shots fired. Reporter: Sources tell ABC news it began when rival motorcycle gangs started fighting, then shooting. We're responding to a gunshot wound in the stairs. Reporter: When it was over, one person stabbed, four hit by gunfire. One man died. People ducking down. People running towards it. People running away from it. A lot of blood on the floor. Reporter: As casualties rolled in, the local emergency room was locked down. Police standing guard. Officers escorted some people to ambulances in handcuffs. Most are members of a motorcycle club. Rather there are local, out of town, that we do not know at this time. Reporter: This is the second recent gathering of bikers to turn violent. Last may, a deadly shootout between the cossacks and the bandinos broke out. The Colorado motorcycle expo is in its 38th year. Drawing in fans with a swap meet, concerts, and a signature wet t-shirt contest. The show may no longer be welcomed in Denver. We're going to have to really assess how this event, if at all, will be held again in our city. Reporter: Now the promoters of the event have not returned our calls or e-mails. The Denver police say they have a person of interest. Today's event, Dan, has been canceled. Wild story, Clayton, thank you.
This transcript has been automatically generated and may not be 100% accurate.