Busted FreeBSD VM ZFS can't find boot block

All,

I'm running a FreeBSD 12.2 VM in VMware Workstation Pro under Windows.

My Windows machine froze, and I couldn't recover except with a hard power
off.

The FreeBSD VM is now complaining, emitting the following lines:

   ZFS: i/o error - all block copies unavailable
   ZFS: can't read MOS object directory
   ZFS: can't find root filesystem
   gptzfsboot: failed to mount default pool zroot

   FreeBSD/x86 boot
   ZFS: i/o error - all block copies unavailable
   ZFS: can't find dataset u
   Default: zroot/<0x0>:
   boot:

I've done a fair amount of STFW, but I'm not seeing how to recover from
this - most of the entries I've found are about performing upgrades of
various sorts..

Can anyone point me to a doco that can help me recover?

I have booted the VM from the bootonly livecd option, but am at a loss as
to how to proceed.

Thanks,
Kurt