According to information received recently, the Sheridans are a related branch of the Carey family. It appears that John Patrick Carey who married [first] Barbara Gilboy [probably in Ireland] was an immigrant to and progenitor of the family in Canada. A Mary Carey, whom I believe to be an older sister of John's, married Edward James Sheridan in Ireland, had 8 children and also emigrated with her family to Canada.
In October 1863, three of Mary's grandchildren by her son James Sheridan, along with an adult Thomas Sheridan age 57 [probably another of Mary's sons and uncle of the deceased children], died from what the record stated was not natural causes, as verified by a jury. The parish records did not state any other details on the deaths. I would think that such an accident or traumatic event would have been reported in a local newspaper - but have no idea how to locate same. I've posted a query on one of the message boards, and hope to hear some suggestions.