The United Mine Workers of America tomorrow will issue its report on the January 2006 disaster at West Virginia's Sago Mine.

The report will offer the union's findings on the causes of the explosion and entrapment that killed 12 miners, as well as recommendations for improving mine safety.

The document will be released at a news conference in Washington, D.C. In addition to UMWA President Cecil Roberts, Sago family members and several members of Congress will attend, including West Virginia U.S. Sens. Robert Byrd and Jay Rockefeller.

The state of West Virginia has already issued two Sago reports, both citing a lightning strike as the probable cause for the methane explosion, although neither could pinpoint how the lightning reached the sealed area underground. International Coal Group, which owns the Sago Mine, also has attributed the disaster to lightning.

The U.S. Mine Safety and Health Administration is expected to issue its report on Sago in April.