Saturday’s southwest Santa Rosa warehouse fire that spread from business to business also damaged 34 vehicles, including classic cars, race cars, excavators and catering trucks, causing as much as $3 million in damage, according to a fire prevention officer.

The structure loss on the West Robles Road property was estimated at $2 million but that total was expected to jump another $1 million because of extensive damage and destruction involving six businesses and the numerous vehicles, said Cyndi Foreman, fire prevention officer for Rincon Valley and Windsor fire agencies.

The cause of the two‑ alarm afternoon blaze remained under investigation Wednesday.

But six video cameras captured where the fire started — a woodworking business — and its spread, Foreman said.

The 5-acre property housed large warehouses busy with a variety of commercial businesses. There were no fire alarms on the building, which dates back to the mid 1900s, Foreman said.

Businesses destroyed included an environmental cleanup service specializing in underground storage tanks at gas stations. That owner lost two trailers full of equipment plus a work truck, as well as the office, Foreman said. Some of the burned businesses involved car work, including restoring classic cars and building specialized racing cars.

Three propane tanks exploded during the fire, helping to spread of the blaze. The damaged vehicles caught in the event all had varying degrees of radiant heat damage.

While the loss was extensive, it could have been worse as firefighters stopped the blaze from spreading to several more industrial businesses close by, as well as kept it from taking hold in a nearby field, Foreman said. “There was a lot of exposure potentially, some really great saves,” she said.

You can reach Staff Writer Randi Rossmann at 707‑521-5412 or randi.rossmann@pressdemocrat.com. On Twitter@rossmannreport.