The German assault on Poland began at 4:45 am on September 1, 1939. The Polish air force, dispersed prior to the invasion, instead of rising en masse to challenge the Luftwaffe, saw its numbers quickly whittled down in a misguided hope to preserve its striking power. The Polish army fought mostly alone, while German planes pounded the Polish capital. Within just two weeks, German artillery and airpower had killed over 60,000 of Warsaw's citizens.