Won't Boot up

An electrical surge would normally burn an enclosure's power electronics, making it incapable of "translating" between your PC USB port and the internal hard disk.

Assuming it's not the USB port which died (try another USB slot to be sure), the disk and its data may be accessed in two ways.

One: dismantle the WD unit, extract the hard disk, and plug it internally into a desktop PC with an appropriate free internal interface (EIDE or SATA), so that no translation is necessary. Data access will also be way faster.

Two: again extract the hard disk, but remount it into an empty USB enclosure - ideally another WD - so that the USB-to-disk translation will take place once more.

Option #2 may be undertaken by the majority of competent PC shop clerks and should cost between US$ 20 and US$ 50, USB enclosure included. Repair shops will often have empty enclosures (maybe even WD's) with good electronics where the internal disk died, e.g. because of a fall.