LONDON (AP) — More than 600,000 vacationers who booked through tour operator Thomas Cook were on edge Sunday, wondering if they will be able to get home, as one of the world’s oldest and biggest travel companies teetered on the edge of collapse. The debt-laden company, which confirmed Friday it was seeking 200 million pounds ($250 million) in funding to avoid going bust, was in talks with shareholders and creditors to stave off failure. A collapse could leave around 150,000 travelers from Britain stranded, along with hundreds of thousands from other countries.