Disk shelf failure

Hi Guys!

Consider we are having 2 bus 0a and 0c  with 5 Enclosures connected to it daisy chained as follows:

What happens when any of the shelfs fails completely? Say if shelf id 2 is failed, will the connectivity to shelf below it(3) will fail?   Also is there any connection from shelf 3 to Bus 0a directly? Or the data from Shelf id 3  has to traverse from 3 to 1 before reaching Bus 0a?