A crowd at the Charleston Embassy Suites hotel listens Tuesday afternoon as United Mine Workers President Cecil Roberts discusses his union's report on the Upper Big Branch Mine Disaster.

Gary and Patty Quarles of Naoma, parents of fallen miner Gary Wayne Quarles, attended the union's news conference, held after a private briefing for families of miners killed at Upper Big Branch.

UMW investigators dubbed the Massey disaster "Industrial Homicide" in a report issued Tuesday.

UMW President Cecil Roberts demanded prosecutions of mine management and corporate officials responsible for conditions that led to the April 5, 2010, disaster that killed 29 miners.