Actually this song predates U2 by several decades. I remeber it being performed by the cbc's singalong Jubilee chorus sometime in the early 60's and a Nova Scotia blue grass band had a version of it out with in couple weeks of the actuall disaster. Like many, if not all, disaster songs this one is a commerative or memorial for the men who died in the disaster. Springhill Nova Scotia (more recently home of Anne Murray) is still a coaling town and could again face the same kind of bump which flattened the Cumberland in 1958.