A list of facts about the Sago Mine

The AP reports the Sago mine near Tallmansville, W.Va., where 13 miners were trapped by an explosion about 6 a.m. Monday was cited by federal inspectors for 46 alleged violations of federal mine health and safety rules during an 11-week review that ended Dec. 22. The more serious alleged violations, resulting in proposed penalties of at least $250 each, involved steps for safeguarding against roof falls, and the mine's plan to control methane and breathable dust. The mine received 208 citations from MSHA during 2005, up from 68 citations in 2004.

According to owner International Coal Group, the mine:

* Was acquired by ICG last March when it bought Anker West Virginia Mining Co., which had been in bankruptcy.

* Has 145 employees. A typical production crew has 10 miners and one foreman.

* Has annual production of 800,000 tons of coal.

* The mine has been producing coal since September 1999 from the Middle Kittanning seam. The average thickness of the seam is 5.5 feet.

* Is a drift mine, which follows a coal seam into a mountain.

* Uses a room and pillar mining system and continuous miners with shuttle cars to remove coal.