LOS ANGELES, Aug. 23 (Xinhua) -- U.S. Congress began its efforts on Thursday to investigate the recent deadly collapse in a Utah coal mine, where six miners remained trapped and feared dead, and three rescue workers died last week.

    The chairman of the U.S. Senate committee that oversees workplace safety asked on Thursday the Department of Labor for a massive load of documents relating to the Crandall Canyon Mine in central Utah, local newspaper the Salt Lake Tribune reported.

    "The loss of life at the mine, and the devastating emotional toll on families of the victims, underscore the urgent need for a thorough examination of our federal system of mine safety," Senator Edward Kennedy said in a letter to the Department.

    The documents requested by Kennedy, who heads the Senate Health, Education, Labor and Pensions Committee, include any petitions to change the mining plan at the site, any inspections performed in the mine, and any notes or memos between the mine operators and the Department's Mine Safety and Health Administration.

    Kennedy's request is likely the first of many investigations the Congress could launch into the Utah disaster on Aug. 6, while another congressional committee has already scheduled the first of what could be many hearings on the tragedy.

    A Senate Appropriations subcommittee set a hearing for Sept. 5,the day after it resumes session. The panel committee has asked for testimony by officials from the federal Mine Safety and Health Administration, the mine and a national mine workers' union.