Death by suffocation through methane gas

Francie, I took your advice and went to St. Michan's Church. Once there, I went down into the vault (you know, the one with the mummies you love so?) and proceeded to get LOCKED IN behind the massive iron door. I was trapped down there for about a half an hour until the tour guide and one of the parishoners/vicar/whatever were walking past to their cars and heard my screams. Not happy.