The city of Sandy Springs’ new 911 call center, also known as ChatComm, will hold an open house April 14 from 10 a.m. to noon and 7 to 9 p.m. Citizens are invited to tour the 911 center at the corner of Barfield Road and Mount Vernon Highway for a behind-the-scenes look at the city’s emergency response services. ChatComm dispatches ambulances, police and firefighters for the cities of Sandy Springs and Johns Creek. Since the center opened last September, dispatchers have answered about 68,000 calls, with an average of 600 calls per day.