The construction of a new $500m medical tower has begun at the Providence Regional Medical Center Everett in the US state of Washington.

The 680,000ft² building will open with about 300 patient rooms ready and will expand to a total capacity of 368 rooms, reports.

The new tower features a new emergency room and can treat up to 150,000 patients each year, the news agency reports.

The new facility is scheduled to open in August 2011.