Tens of thousands of European travelers were stranded today in rail stations, traffic jams and airports as heavy snow and ice caused massive disruption at the start of the Christmas holiday season. In Poland at least 15 people died of exposure, mainly the homeless or careless drunks caught outside in temperatures that plunged to minus 20 Celsius. Forecasters across the continent are expecting more snow and freezing rain over the next couple of days. Roads and railways were closed or disrupted by snow drifts, black ice or floods across northern and Western Europe, from Portugal to the Netherlands, and flights from London, Brussels and Paris airports were delayed. The most crippling problems hit cross-Channel transport between Britain and France, amid chaotic scenes after the Euro star passenger service from London to Paris was shut down following at least five breakdowns.