Propane barbecue caused devastating Foster City condo fire, officials sayA propane BBQ on a first-floor exterior deck caused the massive fire that devastated a Foster City residential complex on Sunday, officials confirmed. A propane BBQ on a first-floor exterior deck caused the massive fire that devastated a Foster City residential complex on Sunday, officials confirmed. A propane BBQ on a first-floor exterior deck caused the massive fire that devastated a Foster City residential complex on Sunday, officials confirmed. A propane BBQ on a first-floor exterior deck caused the massive fire that devastated a Foster City residential complex on Sunday, officials confirmed. FOSTER CITY, Calif. (KGO) -- A propane barbecue on a first-floor exterior deck caused the massive fire that devastated a Foster City residential complex on Sunday, fire officials confirmed.