build block

[norkas]

Pink player is blocking red player's building, right now on #10 DEATH VALLEY.

[norkas]

Pink player was the first to start serving the city, but blocking other players is also wrong. Who is wrong here? Both players r wrong or only pink?

[Chucky]

Pink only.   


See Rule #4: Don't block other players...


or detailed:
5.1. Reserving land/BlockingThe official rules mention already that blocking other players is not allowed. Active blocking is also is forbidden.
Active: Reserving land in front of the spot where another player is currently building to stop him.
"Reserving land" can mean putting rails or other obstructions there or buying land – anything that makes it impossible for another player to build there. Occupy at maximum 50% of the space around an industry/town (or 2 of 4 sides).
As it almost always blocks other players it is basically forbidden to reserve big parts of land – so don't reserve many tiles. Only reserving for minor extensions is allowed.