Hundreds gathered at Thurston Middle School last week to voice concerns about security at Westwood Lodge, a mental health facility. The community meeting was called to address patients leaving the hospital without permission, along with other incidents that have troubled surrounding neighborhoods for years. As part of an evolving safety plan, hospital administrators said a fence surrounding the perimeter of the Clapboardtree Road property will go up this spring. The hospital has also added triple locks to exterior doors after a patient grabbed a swipe card away from a nurse in February and fled to Boston. Local lawmakers have also promised to improve legislation to better serve the needs of mental health facilities around the state. A spokeswoman for Arbour Health System, which runs the Westwood facility, said the state Department of Mental Health has also raised the cap on the number of patients who may stay at the lodge at any one time from 75 to 89 as a result of the hospital’s “successful presentation and implementation of a comprehensive safety plan.”