Cisco switch issue

I have a stack of cisco 3750 switches connected using the stack-wise cables. Hence switch 1 is connected to 2, 2 to 3, 3 to 4 etc. switch 6 is connected back to 1.
 So there is a path to all switches if any switch fails.

here is a show stack output :

 1       Member bc16.650e.3a80     1      3       Ready
 2       Member e4d3.f11e.0300     2      3       Ready
 3       Member 6073.5c30.eb00     5      3       Ready
*4       Master 0006.f6bb.8500     15     3       Ready
 5       Member 6073.5c32.1300     4      3       Ready
 6       Member 4c4e.353a.bb00     3      3       Ready

When I removed the power from switch 1 switches 1 2 and 3 went down 4,5, and 6 stayed up. the sh switch said they were 'removed'.

 1       Member bc16.650e.3a80     1      3       removed
 2       Member e4d3.f11e.0300     2      3       removed
 3       Member 6073.5c30.eb00     5      3       removed
*4       Master 0006.f6bb.8500     15     3       Ready
 5       Member 6073.5c32.1300     4      3       Ready
 6       Member 4c4e.353a.bb00     3      3       Ready

 They came back when I powered on switch 1. I a, confused about this. I have read the cisco stuff on it but I can not get a definative answer regarding if this is normal or not.