A team of federal investigators is expected to arrive Monday in West Virginia as officials try to figure out what caused the blast that killed 29 men in the worst U.S. mining disaster since 1970.
While some of the dead have been laid to rest, efforts continue to recover the bodies of miners still in Massey Energy Co.'s Upper Big Branch mine in Montcoal.
Crews worked Sunday to remove the bodies of several others, but the recovery had to be halted because of high gas readings in the mine.
Authorities have said high levels of volatile methane gas may have played a role in the disaster. Massey has been repeatedly cited and fined for problems with the system that vents methane and for allowing combustible dust to build up.
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