A delayed response to a 911 call has uncovered a deeper issue and now, an investigation has been launched between the Metro Department of Emergency Communications and Nashville Fire Department. 

News 2 began asking questions when it took nearly 20 minutes for emergency personnel to respond to a white powder found at Riverbend Maximum Security Prison in Nashville last Wednesday.

There was a breakdown in communication between 911 dispatchers at the fire department. Now, the DEC says it and the NFD are investigating the error. 

MORE: Dispatch error delays help for white substance found at Riverbend Prison

DEC spokesman Bruce Sanschargrin told News 2 that when 911 operators dispatched firefighters to the scene, operators thought the firefighters could hear an automated message for deployment. But instead, the call was received by firefighters as a “silent dispatch.”

A silent dispatch is electronic and works similarly to a fax machine.

Sanschargrin said the dispatcher’s message was configured for an audio recording while the fire department’s configuration was for a silent dispatch. The configuration was off so the message couldn’t be received.

Two minutes after the dispatch went out, operators realized that no firefighters were en route so they began calling the fire stations and putting out information over the radio.

MORE: Woman reports major issues contacting Metro 911 in an emergency

The closest fire station to Riverbend, Engine 23, was on a medical call and could not respond. Engine 19 was doing in-service training so, while they were available to be dispatched over the radio, the firefighters were not inside the station to receive the dispatch via fax. They could also not be reached by the fire station’s phone line.

Engine 23 was the station to respond first but it took 17 minutes.

There are 12 emergencies that require silent dispatches, including calls for white powder or other possibly-harmful substances. The DEC would not tell us the 11 other emergencies.

The DEC said that silent dispatches are supposed to prevent public panic and protect first responders. 

For example, calls for white powder increased after 9/11. Emergency personnel began privately dispatching first responders to prevent widespread panic.

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Silent dispatches are also used to protect first responders so that the public isn’t aware when emergency personnel is on the scene in certain situations.

Right now, the DEC says it is going over the list of silent dispatches with the NFD to make sure that their configuration is accurate. The DEC also wants to narrow down the list of silent dispatches.