Flames and black smoke poured out of a large soon-to-be demolished chimney at a major fertiliser Napier plant as a fire broke out more than 40 metres up.
Fire crews were called to the fire in the decades-old red and white stacks at the Ravensdown plant in Awatoto about 9.20am on Wednesday.
A Fire and Emergency NZ spokesman said 20 firefighters from three separate stations were on the ground fighting the blaze.
The chimney was ablaze roughly 40 to 50 metres in the air, meaning an aerial fire appliance with a large ladder was also called to fight the fire, he said.
State Highway 51 was closed for a short time to help the fire operations team, with some fears scaffolding on the chimneys could be impacted by the fire.