The owner of an Auckland building gutted by fire hopes security camera footage will give clues about how it started.
More than 60 firefighters were sent to the blaze which gutted the plant off Wharf Road on the Te Atatu Peninsula on Sunday afternoon.
Some of the firefighters had to be decontaminated after getting close to melted chemicals used to make fertiliser.
The fire started in crates leaning against the side of the building, owned by the company Tasti Products.
Chief executive Bryce Howard said he will look through the footage from cameras around the site. He said one person saw some children running away from the factory about the time the fire started.
Auckland Council said some of the melted chemicals seeped into the stormwater system and may have reached Totara Creek, and staff are assessing the situation.