Here there is a lot of unre-enforced masonry and concrete used.
There will be a thorough investigation, this is Germany.

but even buildings using reinforced concrete have been known to collapse. They don't collapse often, so you can count on having this one investigated by an international team that specializes in such things. Busybody Americans will be part of that team, sorry about that, but we have had buildings collapse here, also.

Our latest was Champlain Tower in Surfside, Florida, due to absent maintenance. Greed usually factors into these things along with failing to consider the dead load/live load limits on the original design specs when improvements are added later.

I hope the death toll doesn't increase, that everyone else is pulled out and safe.