A Redmond fire was being investigated as suspicious today, but no cause had been established for the blaze in the downtown area that destroyed a medical office.

The fire was reported about 5:30 a.m. at the offices of the Children's Eye Doctors, 17130 Avondale Way N.E., said Jim Bove, public-information officer for the Redmond Police Department.

Extensive damage was done to the medical office, but other businesses in the complex mainly suffered smoke damage, he said. No dollar value had been placed on the damage.

A K-9 arson-investigation dog from the Seattle Fire Department was brought to the scene.

The fire was rapidly controlled, Bove said, but it took several hours for the scene to cool and allow investigators to enter the structure. The site is on a roadway connecting downtown Redmond to Avondale Road Northeast, a main north-south route through the city leading from Highway 520.