people onboard. a couple and their 19-year-old daughter. >> i don't know what the pilot was thinking or what he was doing, but it's a miracle that no homes were struck. >> reporter: the faa says on average there are about three small aircraft crashes a day in the u.s. this crash is similar to one in march when a twin-engine piper aircraft slammed into an ohio neighborhood, killing the pilot. back here in pennsylvania, the ntsb is still on the scene, trying to uncover what caused this crash. one big mystery, there's no record of any distress calls from that plane. tom? >> such a mystery. all right, diane, thank you. an ominous new report from the united nations about the threat to the world's food supply. more than 100 scientists warn that soil is being lost between 10 and 100 times faster than it is forming, and that climate change, including flooding and drought, is speeding up the loss. but they say there is hope if change comes quickly, including shrinking farmland while growing forest, wasting less food and persuading more people to shift from meat-based to plant-based diets.