Crews clearing Portland hotel fire rubble

The site of the five-alarm fire at Thunderbird On The River hotel has been turned over to the owner, and cleanup is under way.

The mystery of what caused the massive blaze and the owner’s plans for the site are still unknown.

Crews have been working at the site, 1401 N. Hayden Island Drive, for several days. Portland Fire Spokesman Ron Rouse said the fire bureau expects to release information later this week on the status of the investigation into the fire’s cause. A team of 30 specialists from the Bureau of Alcohol, Tobacco, Firearms and Explosives is assisting in the investigation.

The fire, which caused an estimated $5 million in damage, sparked at about 3 a.m. Sept. 2. When firefighters arrived on scene, there were heavy flames coming from the roof of the building, fire officials said. A fifth alarm was called at 4:23 a.m.

The wreckage of the blaze has remained along the river in the weeks since. Portland’s Bureau of Development Services has been investigating a complaint it received on Sept. 17 about the hotel being unsecured because of the structural damage.

Attempts to reach both the Portland inspector and the owner of the hotel, Howard N. Dietrich Jr., were unsuccessful Wednesday.

Property records indicate Thunderbird Hotel LLC buildings and property has an assessed value of $18,824,780.

The Thunderbird has been vacant since 2005. It has a central building and five wings. It was once owned by Vancouver’s Tod McClaskey and Ridgefield’s Ed Pietz, who sold their 54-hotel empire in 1984. The site once was mentioned for a Walmart store, but plans fell through.