Help with TS-XE12TL/R5

[sieve]

A couple of days ago the NAS became inaccessible.  I was able to log in to the web interface at that time.  From what I recall from the logs, disk2 had failed first, but it seems subsequently disk3 and disk4 had also been dropped from the array.  3 simultaneous disk failures seemed unlikely to me, so I initiated a restart from the web interface.  The NAS did not boot back up.  I heard the click of death while it was trying to boot.  I powered off the NAS and proceeded to check the drives in a PC with SystemRescueCD.

Disk2 had failed and would not reach a ready state to get to the boot selection menu of the PC.  On the other 3 drives SMART seems good, and running mdadm --examine shows superblock is intact.  However, the Events count is different for disk1 at 219873 while the count for disk3 and disk4 is 219847.  Also, the Update Time of disk 1 is about 21 hours more recent than disk3 and disk4.  Lastly, the Array State for disk1 is "A..." while disk3 and disk4 show "AAAA".

What should my next steps be?  Can I just boot the NAS with disk2 removed?  I am unsure if the NAS would automatically resync and become accessible in degraded mode since the event count is out of sync.  If it gets to degraded mode, then insert a new disk into the NAS and rebuild?