Chiming in on the fires in Berlin…
Speculation of tunnels under the Berlin Castle (Berliner Schloß): https://twitter.com/iNewsTV/status/1247813110573830144
Another fire at the Humboldt Forum in Berlin: https://www.tagesspiegel.de/berlin/polizei-justiz/rauch-ueber-berliner-stadtschloss-feuer-am-humboldt-forum-eroeffnung-soll-nicht-gefaehrdet-sein/25725916.html
From the article (translated from German to English):
Two "bitumen cookers" with mastic asphalt burned to seal the basement ceiling. This had ignited in the chest-high containers, said the spokesman for the Humboldt Forum, Bernhard Wolter the Tagesspiegel. Bitumen is part of the asphalt.
Mastic asphalt is a mixture of tar and small stones, which is also used in road construction. This layer was applied around the castle and in the building itself in order to seal the cellars underneath against moisture, said Wolter. The construction workers later lay paving or slabs over the poured asphalt.
The mastic asphalt in the stove only started to burn at very high temperatures, but this time it was the case, explained the head of building construction at the Humboldt Forum Foundation in Berlin Palace, Karl-Heinrich Mohr, the Tagesspiegel. As a result, molded glass ignited that had been used for the insulation work.