This newspaper report gives public details about an embarrassing explosion:
“The Coffin Blew Up“, The Meridan [Missouri, USA] Daily Republican, July 21, 1890. (Thanks to investigator Erwin Kompanje for bringing this to our attention.) Here is a reproduction of the entire article:
BONUS (mostly unrelated): The 2012 Ig Nobel Prize for medicine honored the efforts of two doctors to keep modern colonoscopy patients from exploding.