Hewletts Rd was closed by police earlier this morning following a serious incident involving a truck.
Motorists were being diverted around the area - between Aerodrome Rd and Newton St.
Police Inspector Cornell Klussein said a truck had brought down powerlines about 5.50am, understanding the top of the truck had caught the lines.
"Sometimes these lines, something happens to them and they're hanging lower than usual and the top of the truck can catch them," he said.
According to Mount fire service station officer Paul Van Kol, station officer Roger Pickett said a truck with a hoist of some sort on top caught on "a piece of structure from the flyover".