Emergency services arrived at the blaze just after 2.30pm above Pick-A-Part Wingate.
The fire while initially small increased in size as a strong breeze picked up from the south. The Eastern Hutt Road, Peterkin Street and Cambridge Terrace were closed as the fire increased.
Wingate bridge was also closed.
A helicopter from Helipro and eight fire appliances were at the scene fighting the blaze.
By 7.30pm the fire is still been attended to.
No houses were being threatened by the flames.
A large crowd watched throughout the afternoon.
Thanks to Megan Leith for Photos
More comprehensive coverage here from Hutt Valley Fire Police Unit