KEY POINTS:
The Fire Service's report into the fatal explosion and fire at Icepak's Tamahere coolstore says the origin of the flammable atmosphere in the plant room where the explosion was centred was leaking refrigerant, Hychill Minus 50.
It was not possible to say how long the leak had persisted or what caused it.
Ignition was likely to have been electrical. Many items of electrical equipment were in the room. Firefighters carried portable radios that are not intrinsically safe. However, there is no evidence that they used them in the vicinity of the plant room. There is no evidence that firefighters did anything that could have created an ignition source.
April 5 2008
Fire appliances 411 and 412, carrying eight firefighters from Hamilton, attended a report of a smoke alarm having activated. Appliance 411 arrived at 4:14pm, appliance 412 arriving soon after, at the Tamahere site near the city.
4:21pm
Several firefighters reported seeing smoke, gas, mist, haze, steam or vapour coming from the plant room area. Two said they noticed a smell like lemon or almonds. Other firefighters do not recall the smoke or vapour having any smell. None reported a smell of gas.
4:28
Three firefighters from 411 made entry to the building and began searching the plant room. The room was an open area and there was enough light so that torches were not needed. The room contained what appeared to be refrigeration motors and compressors.
Firefighter 1 noticed a loud hissing noise and found a small pipe leaking gas. He called out to advise the others. The officer in charge of 411 joined him. The pipe was about 5mm in diameter. The leak was coming from around a joint in the pipe that was secured with a small hexagonal nut. Firefighter 1 informed the officer that he would go to the fire appliance and get a crescent spanner to tighten the connection to stop the leak.
Firefighter 1 left to get the spanner. The officer and firefighter 2 examined the leak. Both men in turn compressed the leak with their fingers and it would stop.
Firefighter 1 had trouble reopening the door through which they had entered the building. The driver of 412 got a crowbar and used this to ease the door open allowing firefighter 1 to exit. From the doorway the driver could hear hissing - "a high-pressure type sound".
4:29:47
The driver of 411 sent a radio message, "entry gained, brigade investigating". After putting in the message he got down off the appliance and started to walk towards the officer of 412.
4:30
At that moment the explosion occurred.
The driver of 412, standing in the doorway of the building, described a loud explosion and flames erupting right beside him from behind the door. The force blew him tumbling about eight metres and when he stood up he didn't know which way to run because he was surrounded by flames. The fireball evaporated; he saw 412 and headed for it.
The driver of 411 does not recall being knocked over by the explosion. He too headed for 412 and found the driver of 412 sending a priority radio message. The driver of 411 took over the radio and transmitted a voice message.
4:30:29
Voice message sent: "Transmit second alarm, major explosion." He immediately sent a radio message code requesting ambulance attendance.
