With two drive failures in a RAID5, you have most likely lost the data.
You can try finding 3 drives that boot the system correctly, I have seen situations where one bad drive made another appear to fail. Shut down, remove the first failed drive, and reboot. If the data is not accessible then shut down, put that one back in, and take out the other failed drive. Try again.
If this doesn't work in either configuration, you will need to replace those drives, recreate the array, and restore from backup.
