The 58-year-old man suffered fatal injuries after becoming trapped by heavy machinery.
Police and the Health and Safety Executive are investigating the incident, which happened just after 8am yesterday. (Tuesday)
The man, , who has not been named, was working on a new tourist attraction to extend a deep underground roadway at the Overton Colliery.
He was taken to Pinderfields Hospital where he later died.
A museum spokeswoman said the museum would be closed today as a mark of respect. She added: “The museum is very saddened by this incident, and extends its deepest sympathy to the family, friends and work colleagues of the man.”