OLYMPIA, Wash. (AP) - The roof of a riding arena in Olympia collapsed early Saturday under the weight of rain-soaked snow.

Co-owner Cathy Noyes said owners of Sherman Valley Ranch, a horse- and dog-boarding facility, had been working for several days to clear the snow from the 76- by 156-foot roof.

No horses or dogs were injured.

Noyes said she and helpers had turned the horses out into the snow-covered fields just in case. She said the kennel area for dogs was safe.

The roof collapsed just after 1 a.m. It arena was attached to a barn, which contains an office and an apartment.

Saturday's incident is the latest in a series of roofs that have collapsed under the weight of heavy, wet snow as Western Washington thaws out from the past week of snow and ice.

In Arlington, city officials condemned the building, located at 19406 68th Drive NE, after its roof collapsed. The structure is occupied by a business identified as West Coast Forest Products.

No one was inside the building at the time of the cave-in, and no one was hurt, officials said. A damage estimate was not immediately available.

In Bothell, a firefighter was working under a carport at about 4:50 p.m. Friday as he responded to an earlier medical aid call at the Green Acres Mobile Home Park. Without warning, the carport roof collapsed on him.

The firefighter was extricated from under the structure and transported to Harborview Medical Center in Seattle for treatment of his injuries. The extent of injuries were not immediately available. The patient from the earlier aid call was not injured by the roof collapse and was taken to a local hospital for treatment of chest pains.

Friday's incidents were but the latest in a series that began Sunday as several inches of snow and ice began accumulating.

In the previous incidents:

- A large tent covering the ice skating rink at Bellevue's Magic Season festival collapsed Sunday evening, briefly trapping 10 people under a pile of snow and ice. One young girl was treated for minor injuries.

- The roof and walls partially collapsed at a factory near Marysville on Monday, severing gas and sprinkler lines and creating a huge mess inside the building. No one was hurt.

- A section of the roof caved in at Capital High School in Olympia early Thursday, sending a cascade of water and snow into the school.

And carport roofs were reported to be collapsing all around the Puget Sound region, from Olympia to Snohomish County, under the weight of the heavy snow.

The potential danger prompted officials to issue warnings to local residents.

"The rains and snow mixture may create growing snow loads on rooftops, which could cause safety hazards such as structural collapse or sliding snow," said Lynne Miller of the King County Office of Emergency Management.