Seton Medical Center’s Coastside emergency room in Moss Beach is set to temporarily close for nine months beginning Monday, April 1. County Supervisor Ray Mueller said he was “deeply troubled” by Seton’s “lack of public transparency” about the need to close the emergency room at all. “You have people coming in who are suffering, who may be having a heart attack. They could have a whole myriad of acute ailments that require a visit to an emergency room,” Mueller said.