Don't panic! Taylor Swift warns fans to expect sirens for WWII anniversary in Warsaw before concert

Taylor Swift is telling fans traveling to her first concert in Warsaw this week to not panic when they hear sirens. Those sirens will wail Thursday at 5 p.m. to honor a key World War II anniversary. Across the Polish capital observances are being held to mark 80 years since the start of the 1944 Warsaw Uprising, which was a 63-day revolt by Polish insurgents and civilians after five years of brutal Nazi German occupation. The entire city stops and alarm sirens sound every Aug. 1 at the exact time when the ill-fated revolt was launched.