Thousands of hotel workers across the U.S. went on strike on Sunday, the first of many days of planned work stoppages that could greatly impact guest experiences over the next few weeks. Members of the UNITE HERE union, which includes employees of Hilton, Hyatt, and Marriott in 24 cities including Boston, San Francisco, Honolulu, and Seattle, went on strike on Sunday, during the busy Labor Day weekend, as the union continues contract negotiations with the hotel companies. The growing list of properties includes major hotels such as Fairmont Copley Plaza and Hilton Boston Park Plaza in Boston, The Royal Hawaiian and Sheraton Waikiki in Honolulu, and the Grand Hyatt Union Square and Hilton Union Square in San Francisco. UNITE HERE says each strike will last two or three days and that strikes in other cities, including Baltimore, Oakland, and Providence, could "begin at any time." The full list of properties impacted is available through the UNITE HERE website.