A man is fighting for life and another was also injured when they were caught in a violent fireball that erupted at Mount Maunganui's industrial zone yesterday.
A 63-year-old man suffered serious burns to his face, head, upper torso, arms and hands and is today in a critical condition in Waikato Hospital's intensive care unit.
Another 63-year-old received moderate burns to his face and arms and was discharged from Tauranga Hospital yesterday afternoon.
The burns to both men were so severe that skin started peeling off their faces and arms. They were caught in a fireball described as being as big as the 20-foot wood chip container it blew out of at about 11am.
They had been standing next to a sawdust-extracting machine (bag-house) and the container at a wood re-manufacturing plant in Hocking St when they were engulfed in the "firebomb".
The Trayco employees had stopped work after smelling something strange coming from the machine, business owner Graeme Woolley told the Bay of Plenty Times.
"They thought a piece of wood was jammed in the fan, then it all of a sudden exploded."
The fireball shot from the container, flames ballooning above the timber plant.
Farmer Auto Village's Peter Wilson described it as a "firebomb".
Mr Wilson was standing in his workplace's cafeteria at the time. He saw the flames shoot out of the top of the building then disappear within a second.
"It was massive, I've never seen anything like it in my life. It just went up and around the building ... the flames were huge."
Mr Wilson said he could almost feel the aftershock. "It was almost like a bit of thunder, just a really loud boom."
Mr Wilson said he blinked and the flames disappeared.
A woman working in the Trayco office said she heard the bang and knew straight away "it was not good".
The woman, who spoke on condition she was not named, was in an upstairs office about 100m away.
"After the bang I looked out and I could see that it was a major. I saw everyone running around like chickens with their heads cut off so I called the fire brigade and ambulance."
A group of electricians working across the road heard the fire alarm sounding at Trayco.
"A little bit after that fire engines came out, then we saw the ambulances come and the cops came after that," said Simon Hood.
Also among the group was Richard Pope, whose friend worked at Trayco and was waiting on the road for the ambulance when he told him: "It just went bang and some dude's face and hands were burnt."
Tauranga Fire Brigade station officer Phil Price said the explosion blew off the doors of the container. The man standing closest to it suffered the worst injuries, as he was not wearing overalls, Mr Price said.
There were three further explosions following the initial blast and fire also broke out inside the container.
Mr Price said the possibility of something becoming jammed in the fan created a "very volatile situation".
"The air can be very explosive because when it's filled with small particles or other matter, like flour, grain, sawdust or even small metals, and when you have an ignition source - such as the friction build-up - it can explode in seconds."
The fire inside the machine was controlled by an internal sprinkler system. When firefighters arrived, the fire in the container was still ablaze and a forklift was used to move the container about 10m away so they had easier access.
Firefighters who helped the men said their burns were so serious, skin was starting to peel off their faces.
Mount Maunganui upskilled paramedic Chris Jones said the most seriously injured man cooled his arms in a sink while his colleagues emptied a water cooler over the top of his head.
"It was really good. He was over the sink cooling his arms, but the burns to his skull and face ... they were running water over him. It was very well done."
Mr Jones said it could take 20 minutes to cool a burn naturally, so it was vital to try to cool a burn straight away.
It is understood the men have been employees of Trayco for many years. The sawdust-extracting machine was worth about $150,000 and installed late last year.
Trayco's Mr Woolley has been in the industry about 30 years and said he had never seen an explosion like this before. "I've heard of it happening but never seen it. It's quite rare."