software raid - degraded mdadm RAID5 array

My /dev/md0 array just died last night. I got this email

This is an automatically generated mail message from mdadm running on

A Fail event had been detected on md device /dev/md0.

It could be related to component device /dev/sdb.

Faithfully yours, etc.

P.S. The /proc/mdstat file currently contains the following:

Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdb0
sde[4] sdd[2] sdc1
4395411456 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/2] [__UU]

unused devices:

So, i had to pull the plug :(

After reboot, array failed to restart.

mdadm -A /dev/md0

mdadm: /dev/md0 assembled from 2 drives - not enough to start the array.

cat /proc/mdstat

Personalities :
md0 : inactive sdd[2](S) sde[4](S) sdc[1](S) sdb[0](S)
      5860550240 blocks super 1.2
unused devices: 

and

mdadm --assemble --force --verbose /dev/md0 /dev/sdc /dev/sdb

mdadm: looking for devices for /dev/md0
mdadm: /dev/sdc is identified as a member of /dev/md0, slot 1.
mdadm: /dev/sdb is identified as a member of /dev/md0, slot 0.
mdadm: added /dev/sdc to /dev/md0 as 1
mdadm: no uptodate device for slot 2 of /dev/md0
mdadm: no uptodate device for slot 3 of /dev/md0
mdadm: added /dev/sdb to /dev/md0 as 0
mdadm: /dev/md0 assembled from 2 drives - not enough to start the array.

Ideas?

Thank you