You are assuming the Rapture 'kicks off the Tribulation'. It may in fact be many days or even weeks or months before the last week of Daniel's seventy weeks 'kicks off'. Once the True Spiritual Church is harvested from the Earth, it may take months for the chaos to settle enough and world-wide communications to be restored, such that the man of sin can saunter onto the scene and make a safety treaty with Israel. That is one reason some of us are proclaiming that the Rapture is very close.
People are being beheaded for Jesus at this very moment. The fifth seal is upon us and no worldwide plane/train crashes.