UPDATED 5PM: Power is out in parts of Greerton and Gate Pa after a tree being felled came down on high voltage power lines this afternoon.

Power was cut to about 5000 properties in Gate Pa, Greerton, Merivale, Bethlehem and Judea about 3.45pm as a result.

Supply has been restored to 4000 customers with the remaining 1000 Greerton and Gate Pa properties expected to have power back about 6pm.

Powerco acting network operations manager Phil Marsh says the person cutting the tree had put themselves in danger by working close to overhead lines.

'Trimming trees or vegetation near power lines can kill. They're extremely lucky not to have been seriously injured.”

He says Powerco has a rigorous process that everyone must follow to work near live lines.

Powerco approved tree trimming services must be used if vegetation or trees are within 4m of power lines.

'We understand how dangerous it is – even for us professionals. Knowing this makes it hard to comprehend why people think they can trim trees near power lines without following this process.”

Phil says electricity can jump across objects like tree branches or equipment if they are close enough.

'Trees conduct electricity and so do people.

'Most of the lines around here are at least 11,000 volts – that's more than enough to kill a person.”