What is possibly one of the art world's greatest finds came about because some French homeowners wanted to fix a leaky roof. The 400-year-old work, which was found by accident in 2014 in an attic of a house in Toulouse, is thought to have been painted by Italian master Caravaggio, according to Old Masters expert Eric Turquin, who has been studying it for the past two years. The amazing find was discovered in a sealed-off part of the attic space, which had to be accessed in order to repair a leak. Named "Judith Beheading Holofernes," the painting represents the biblical...