Strange occurrence can anyone explain

powercut/power surge

 

Ghosts.

 

Not too likely, unless all laptops were running on adapter only, with dead or no battery.
Even one with a battery with some charge, would simply run off the battery, and not affected at all by a power surge - same as just pulling the power cord.

"...restarted at the exact same time …" from 3 separate locations couldn't be called "random" IMHO.

The OP has left some important detail out.

One possibility that makes sense - all MacBook Pros are connected to the same server (not just to the same router), with controlling software like Apple Remote Desktop sending a restart command to all connected computers.

 

http://en.wikipedia.org/wiki/Electromagnetic_pulse

 

Something like Revolution is happening? http://www.imdb.com/title/tt2070791/