State Fire Marshall Investigation Results
A team from the Office of the State Fire Marshall (Utah) investigated for two days and were successful in determining the exact location and cause of the fire. In short, there was an electrical "event" of the aluminum wiring enclosed in a conduit running along the outside back of the house. Part of this conduit (running along the side of the house) can be seen in the photo (right). The aluminum wiring heated up, arced and started burning inside the conduit. Once the temperature reached 2700 degrees the conduit melted through and the fire quickly spread to the back sunroom of the house and deck. The explosion heard early by witnesses was the propane tank from the grill located on the deck, fairly close to where the fire first stared. This spread the fire very quickly into the garage area.
We'd like to thank Steve Higley, Bryan Thatcher (Deputy State Fire Marshalls) and their team (State of Utah, Department of Public Safety) for their professionalism and thorough work.
Check back for the official report, as it will be posted here soon...
And if you think your home may be one of the estimated 2 million homes with aluminum wiring (typically built/remodeled in the mid 60's to early 70's), check out this article in the NY Times regarding The Fire Dangers of Aluminum Wiring