A 33-year-old German man has been detained after a fire ripped through Hitler’s mountaintop retreat, the Kehlsteinhaus, also known as the Eagle’s Nest, in Bavaria. Fire alarms were received at 21:15 local time on Friday, and firefighters found the building engulfed in flames. Police said difficult terrain hampered efforts to bring the fire under control, with around 200 emergency personnel still deployed as the blaze burned into early Saturday. Officers apprehended the man while he was riding a motorcycle near the scene, German media reported. A criminal investigation has been opened. Investigators said there is currently nothing to suggest further suspects. Prosecutor Rainer Vietze said a psychiatric report indicated signs of possible mental illness, meaning diminished responsibility might be assumed, and that a possible political motive was also being considered while the case remains in its early stages. The Eagle’s Nest, completed by the Nazis in 1938 above Berchtesgaden, was one of several buildings used by Hitler and his entourage during World War Two. Local media said the site was largely destroyed, and Bavaria’s Interior Minister Joachim Herrmann said it would not remain a ruin.