1950s - Color, USA, Mining Safety: For Miners Returning To Work (methane gas accumulation)

For Miners Returning To Work (methane gas accumulation) Bureau of Mines safety announcement for bituminous coal miners warning of possible methane gas build up during miners’ strike; roof supports could have deteriorated; mines may have dried out causing possible dust explosions. “You can help avoid accidents....” 1950s (?); 1960s (?); Work Place Dangers; Mine Safety;