FORT WORTH -- After a faulty circuit breaker triggered an outage in the 911 system Monday night, officials said Tuesday that improvements will be made.The system went down at 6:15 p.m., was switched to Arlington's dispatch center at 6:39 and was fully running again at 7:20, Fort Worth Fire Chief Rudy Jackson said.Tarrant County 911 reported that the Fort Worth system missed 224 calls, likely between the time its system went down and Arlington's picked up, Jackson said. Arlington took 27 calls and relayed them to Fort Worth, which dispatched personnel by radio, he said.Normal volume for that period is 150 calls, Jackson said."We had several test calls going back and forth, trying to figure out what was going on," which increased the volume of missed calls, Jackson said.The problem followed a routine system test, officials said.After the test, a circuit breaker popped, causing the 911 system to lose hard-line power, said Doug Wiersig, the city's transportation and public works director.The system reverted to battery backup. Employees mistakenly believed that they had fixed the problem, but the system continued to operate on battery power, Wiersig said.The battery backup began sending warning messages, but the modem wasn't working, so the messages didn't transmit, Wiersig said. The 911 system went out when the battery power ran down, Wiersig said.At that point, workers moved to transfer the system to Arlington but couldn't without power. Working with the city's telecom provider, workers manually threw a switch that transferred the system to Arlington, Wiersig said.The bad breaker and modem will be replaced and more backups and alarms installed, he said.Safe CommunitiesFort Worth officially received a Safe Communities designation at Tuesday's City Council meeting, signifying the city's interest in reducing injuries.Twenty-three other entities in the U.S. and 299 worldwide have received the designation.Safe Communities America conferred the designation on behalf of the World Health Organization's Collaborating Centre on Community Safety Promotion. The organization is a program of the National Safety Council.The Fort Worth Emergency Services Collaborative organized a 130-member committee that launched programs including educating nurses to watch for signs of domestic abuse and placing "Take Back" medication boxes at three police substations in neighborhoods with high overdose rates.