I checked the mining accident records that I have for WV, PA, KY and OH and I found nothing for Guiseppe Pantaleo.. However, he maybe did not die in a mining accident. This is an unusual name and they probably butchered the surname, but I would assume that the first name got spelled correctly in the death records, but even it could be spelled Gusippe, Guseppi, Guissippi, Guesseppi, Gussppi, Guisseppe. I would recommend that you try to locate him or his survivors in the census, so that you have a county to work with.
Perhaps you can find help on these web sites:
Census records can be searched on-line for free through Heritage Quest. This research tool is available through most major libraries if you have a library card with them. The link can usually be found under the library’s web page usually under the category “Research Resources or Tools - Databases”.http://www.linkpendium.com/https://beta.familysearch.org/
“LDS Family Search” If you place your browser on the name on the left, more information comes up. Their search includes census records. http://www.findagrave.com/ http://www.deathindexes.com/ http://search.ancestry.com/search/ http://www.wvculture.org/vrr/va_dcsearch.aspx
“West Virginia Death Records”http://www.wvculture.org/vrr/
“West Virginia Vital Records”
“Mining Accidents U.S., Canada, New Zealand and Australia”