He went to extremes. A 27-year-old Syrian was barred from entering a music festival in the town of Ansbach last night before he detonated a backpack explosive, killing himself and injuring 15. The area was evacuated, and German authorities say they’ve found a video of him proclaiming allegiance to ISIS on his phone. The man — who was denied asylum a year ago in Germany — was known to have had a history of mental illness. Authorities are now studying the content of Islamist videos found on his equipment.