ANTAKYA/KAHRAMANMARAS, Turkey, Feb 18 (Reuters) - More than 46,000 people have been killed in the earthquake that struck Turkey and Syria and the toll is expected to soar, with some 345,000 apartments in Turkey now known to have been destroyed, and many still missing. As Turkey attempts to manage its worst modern disaster, concerns were growing over the victims of the tragedy in Syria, with the World Food Programme (WFP) pressuring authorities in the northwest to stop blocking access to the area as it seeks to help hundreds of thousands of people ravaged by earthquakes. See here for a complete list of exchanges and delays