Two firefighting helicopter crew members died in a midair collision on Sunday while battling a major wildfire west of Athens, as Greece enters its second week of blazes driven by extreme winds. Five water-dropping planes and another five helicopters took off at first light Monday to support hundreds of firefighters on the ground. The collision happened near Porto Germeno, a coastal area west of Athens, where crews had been working to contain the fire. The wildfire is part of what officials describe as a volatile European wildfire season that started early and intensified quickly. Winds reaching 100 kilometers per hour have spread the flames and hampered firefighting efforts. The deaths underscore the dangers faced by crews across southern Europe, where climate change is intensifying wildfires.