DALLAS (CBSDFW.COM) – Tech teams worked early Tuesday to fix computer systems for the City of Dallas after detecting a virus that impacted a number of operations, including the 911 dispatch center. The system is responsible for dispatching first responders to emergencies.

Officials said that the virus was detected early Monday. It slowed down computer programs and limited access to systems. It is not know how the virus got into the city’s computer network, but it is not believed that any personal data was compromised or stolen before it was discovered.

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(credit: CBSDFW.COM)

The virus inundated several city computers. The the 911 system was back online quickly, but other systems took longer to fix.

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While the computer-aided dispatch system was impacted, the city’s ability to actually receive and respond to 911 calls was not affected. A city spokeswoman explained that the computer problems simply changed the way that dispatchers received reports and entered them into the system.

People also reported trouble accessing the public library’s online catalog and municipal court records on Monday. Everybody who had a municipal court case set for Monday had to reschedule. All systems across the city were restored by early Tuesday morning.

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Somebody had previously hacked the citywide emergency sirens in April of last year, causing false alarms to sound loudly for hours. That led to an investigation by the Dallas Police Department and the FBI. There has been no indication that the virus is related, however.