Unbelievable. Building contractors over the ground keep boring into the tunnels underneath for "geological surveys".

It happened several years ago in Japan when somoone drilled into a train tunnel for "geological survey". And a train hit it!

https://www.asahi.com/sp/ajw/articles/13060489

Now exact same happened in Turkey!

Someone there also bored a contractor into a metro tunnel. Luckily the drill damaged the electricity supply to train preventing a major accident.

Here in the video see the drill still boring away in the rails.

I learned about this in Turkish tunnel group:

https://tunnelcontact.com/discussion/view/54571/sordaj-delgisi-istanbul-havaalani-tunelinin-tavanini-deldi