You're leaving out evaporation. A black hole with the mass of a mountain would evaporate on the order of a second. That would also release energy the equivalen

You're leaving out evaporation. A black hole with the mass of a mountain would evaporate on the order of a second. That would also release energy the equivalent of ~20M megatons of TNT, which is half a million times that of Tsar Bomba and around that of the KT event. The Swiss wouldn't be too upset about anything.