For Katie Andrews of Missouri, the outer glass in her Kenmore oven. Andrews said the oven hadn't been used all day. The manufacturers each had similar reactions. Sears, which owns Kenmore, said it takes product safety issues very seriously. In earlier reports about Andrews' case, spokesman Larry Costello said a glass door can break as result of a micro-fracture. By email, Costello told the Problem Solvers, "This is not a safety concern - the tempered glass is designed to 'pebble.'" Electrolux, which makes Frigidaire, said it too is serious about safety. By email, spokeswoman Eloise Hale said, "We take the safety of our products seriously and work diligently with industry regulators to ensure the glass used in oven doors is performing as expected." Both Sears and Electrolux point out that the glass in all their ovens are in compliance with federal and industry safety standards. After being made aware of Betty Chan's case, Bosch agreed to investigate.