RENTON, Wash. -- An unoccupied apartment building was swallowed in a massive five-alarm fire that erupted in Renton Tuesday night.

Firefighters continued to pour water on the Harrington Square complex Wednesday in the Renton Highlands area after the building was burned up in an inferno of flame that erupted at 8:01 p.m.

The complex consists of two buildings. The five-story building that burned was under construction and slated to open in 2010. Workers had been at the site earlier Tuesday.

Harrington Square manager Shama Ross said she was inside tower 1, which is complete, when she heard popping sounds coming from tower 2.

"I came out and saw the corner of the building smoking. That's when we called the Fire Department," said Ross.

The fire quickly escalated to five-alarm status as the building became engulfed in flames. More than 100 firefighters joined the effort from Bellevue, Seattle, Kirkland, Woodinville, Tukwila, Kent and Eastside fire departments.

Firefighters evacuated 10 to 15 nearby homes as a precaution. Officials were concerned that wind would carry flames to homes in the area.

Smoke from the spectacular fire was visible from both Interstate 90 and Interstate 5 in the Seattle area and caused hundreds of spectators to converge at a nearby playfield to watch and take pictures.

Fire officials said the tower that burned was 60 percent complete, and because it didn't yet have sprinklers installed, the building burned up quickly.

Officials said it could be days before the cause of the fire is determined.

There were no injuries related to the fire but a Renton police officer was hit by a pickup while directing traffic. He was treated and released from a hospital.