"Well, I didn't know it at the time, but we were running on backup power," Arnold said.

The backup power was working within 30 minutes.

Or indeed the excess pollution and waste from the hot backup power needed to support them.

Traffic lights, which had no backup power, were all knocked out.

If there just isn't enough light, solar water generators are often equipped with electrical backup power.

And so are the computers-cut in the backup power, somebody!

Only 10-20% of the electrical backup power is needed.

All four engines failed leaving only critical systems on backup electrical power.

Other major concerns in New York have taken steps to improve their backup power and computer operations.

Good response time, reasonable reactions, though the diagnostics shouldn't have been run until after the backup power took over.