A runaway truck hauling tons of gravel flew off an embankment Tuesday after its brakes failed and crushed a home, killing a man, woman and child, authorities said.Wow. I thought the far West Chicago suburbs were the only place these things happened.Thanks to the glaciers, Illinois around Chicago has huge deposits of high-quality gravel. The streets in the older suburbs are from the 1920's, so they are narrow and hug rivers, bridges, hills, etc. Just about every car has gravel dings in their windshields, from all the gravel trucks. A standard truckload is around 13 tons of gravel. In the 20 years we lived in Algonquin, twice there was a turnover accident at one particular city-street intersection with a tight turn to get onto the bridge. Gravel flows like water, so when a truck overturns, the entire load just FLOWS over whatever is under it. 14 tons on gravel dumped onto a car waiting for the light to change distributes that weight pretty evenly -- crushing it pretty flat.