The most probable loss scenario for underground traffic facilities (tunnels, railway stations) is an uncontrollable fire.

对于地下交通设施（隧道、地铁站），最有可能的损失情况是失去控制的火灾。

youdao

Yet it is just the highest profile in a string of big-ticket projects including a concert hall in Hamburg, railway tunnels in Munich and Leipzig, a subway line in Cologne and a Stuttgart underground train station that have been plagued by huge cost overruns and delays.

NPR: Berlin's Airport Project Delays Shame Germans