London; Ont.; Firemen hose down debris that is all that remains of the Forster house; destroyed by a natural-gas explosion. Nine-year-old Armin Forster was alone in the house when he heard a pop ; saw the kitchen stove ablaze and ran from the house. At least 10 houses were destroyed and 28 damaged as a series of explosions rocked a 10-block area. Police evacuated about 3;000 homes; 700 of which use gas; residents were allowed back in their homes last night.