The collision laid bare the danger at the most volatile front of Europe’s wildfire emergency. Flames bore down deeper into the region of the Greek capital, forcing fresh evacuations in the early hours of Monday. The blaze raged through pine forests and scrubland through the weekend, whipped by gale force winds that often prevented water-dropping planes from operating. Foreign firefighting and helicopter crews are often deployed in Greece to help tackle wildfires during the country’s hot, dry summers. Greece has devastating wildfires every summer, with hot, dry conditions and frequently strong winds making it easy for small sparks to trigger major blazes.