A private airplane crashed in anorthern Mexico city, killing all eight people aboard, authorities said Monday. Civil Protection official Francisco Contreras said the Hawker 800 luxury jet hit theroof of a warehouse as it approached the airport in foggy conditions in the city ofSaltillo. It burst into flames, crashed into the ground, and broke into pieces thatscattered over 400 meters.On board were the two pilots, two married couples, one child, and one woman.Contreras said firefighters took one hour to extinguish the flames. Emergencypersonnel were attempting to recover the bodies and the airplane’s data and voicerecorder.The cause of the crash was not yet known, but Contreras said the thick fog likelycontributed.