The Boston Fire Department tweeted last night:
Incident Response: Tech Rescue response for Barnes & Noble bookstore at 660 Beacon St. Kenmore Square. at 11:22pm.
Incident Update: Small one foot square piece of morter fell to sidewalk. No injuries. Turned building over to BU (owner) to secure. 12:30 am
Final Incident Update: Six story building. Morter fell from top. BU will have engineer check further in the morning. Sidewalk closed for now