WASHINGTON -- A leading House Democrat wants federal prosecutors to open a criminal investigation into the deaths of nine people in a Utah mine collapse last year.

Democratic Rep. George Miller, of California, is the chairman of the House Education and Labor Committee. Miller says his investigation into the August 2007 deaths at Crandall Canyon led him to make a criminal referral to the Justice Department.

Miller says UtahAmerican Energy may have misled federal mine safety inspectors on how safe the mine was. He says investigation shows the company may have downplayed a "bump" that burst pillars in another section of the mine months before the accident.

The Labor Department is still investigating the Crandall Canyon collapse.