When the roof was replaced you'd hope that a top quality impermeable ice-and-water-shield adhesive membrane would have been used to line the whole problem area and also that the size of the valley and downspout were made big-enough with necessary deflector to be sure water goes into the g...
Underground tunnels, mines, water systems can often collapse if they are not constructed properly or have significantly aged. The more common way in which sinkholes can form are natural. Volcanic activity, below the surface of the earth, sometimes create large holes that can collapse under the ...