MacBook turned off during Time Machine initial back up - What do I do? My external hard disk was partitioned to 3 partitions and one of which (300 GB) was set up with Time Machine. The initial back up started and was 3 hours through (around 65% of 211 GB complete). I lost track of time and my MacBook turned off on zero battery power.

When I turned it back on, it says that the disk was not ejected properly. When the external hard disk was re-connected, I don't see the Time Machine icon on my TM partition any more. Time Machine status states that the backup was delayed. When I gave the "back up now" option, the Time Machine started normally with status 10 MB out of 85 GB. After a while, the back up was complete.

My question is simple: would my backup be corrupt due to this incident? Is there anything I should do to ensure it? Or is everything just fine and that there is nothing to worry about?
It would be hard to tell with out looking at the backup. If I was in you situation and I was not sure if the first backup was successful I would wipe that partition and start again (assuming when you say initial backup you mean the first ever!)

From my personal experience however when similar things have happened to me during a backup I've had no corruption issues. This being said it was not my first ever Time Machine backup.

Honestly the safest thing to do is wipe that partition and start again (assuming when you say initial backup you mean the first ever!)