It is thought that these discharges take place when a powerful positively-charged bolt of lightning strikes the ground.

But the demands of success hit them like a bolt of lightning.

To me it was like a bolt of lightning out of a clear sky.

The bolt of lightning had struck the roof aerial and sent a huge electric charge down to the set.

Then, without warning, a blinding bolt of lightning struck down into the pit, lighting the black depths in a bright flash of incandescence.