New York City Council members pressed Office of Technology and Innovation services (OTI) at a City Hall hearing on September 9 over a nearly seven-hour 911 disruption on August 18 that left 113 unique callers without confirmed emergency assistance, questioning how the failure went undetected for hours and why the public was not immediately notified.

The August 18 disruption followed a software upgrade performed by Motorola Solutions, the vendor that provides the city’s 911 call services infrastructure. City officials testified that the upgrade triggered the problem but said an investigation into the outage and responsibility for it remained underway.

“What happened last month at the Bronx 911 call center, a seven hour outage with very little to no notice to the public, is unacceptable,” said Council Member Oswald Feliz, chair of the Committee on Public Safety.

New York City’s 911 system receives more than 9 million calls annually and operates through two emergency communications centers: Public Safety Answering Center, PSAC-1 in Brooklyn, and PSAC-2 in the Bronx. Each is equipped to independently handle the city’s typical daily volume of approximately 25,000 calls.

According to testimony, Motorola began upgrading firewalls in PSAC-2’s routing environment at 9:45 pm Aug. 17. The work was completed at 4:13 am Aug. 18 and was initially believed to have been successful. Investigators later determined that problems with calls had begun at approximately 3:13 am.

The first indication of trouble came shortly before 6 am, when a call taker reported difficulty hearing some callers. Officials initially believed the problem was limited to two call taking positions.

As reports increased, it became clear that Motorola and Verizon were having difficulty interfacing. Officials eventually discovered that some people calling 911 could not hear emergency operators answering them.

By approximately 9:50 am, officials determined that calls routed through PSAC-2 were affected while PSAC-1’s routing system remained functional. Motorola redirected traffic through Brooklyn, and by 10:19 am, officials said service was operating normally.

The administration acknowledged that the problem should have been detected sooner.

“It wasn’t caught, and obviously it should have been,” Lisa Gelobter, the city’s Chief Technology Officer, testified.

Preliminary figures showed that 5,489 calls were made to emergency services between 3:13 am and 10:19 am, including 911 and alarm company calls. Approximately 3,800, or 70%, were handled without problems, while 1,696 encountered issues.

Of the affected calls, 742 were 911 calls originating from 319 unique phone numbers. Officials said 206 of those callers eventually connected with an operator, leaving 113 unique numbers that were not serviced.

The testimony reviewed for this story did not establish whether anyone was injured or died because of the disruption or what emergencies were associated with the 113 callers.

Council members also focused on why New Yorkers were not immediately notified about the problem or advised about alternative ways to seek emergency assistance.

“Failing to properly inform the public about something as important as the 911 system being out, that is not a technical glitch,” Feliz said. “That is a human choice, an unacceptable one.”

Council Member Joann Ariola, chair of the Committee on Fire and Emergency Management said, “It is paramount that we, as a city, provide life-saving responses to fire and medical emergencies,” stating the outage threatened the city’s ability to provide timely emergency assistance.

Officials said Motorola’s upgrade triggered the disruption but stopped short of assigning final responsibility. A response from Motorola was not included in the portion of hearing testimony reviewed for this story.

The outage demonstrated the stakes of failures involving a system New Yorkers depend on during their most vulnerable moments.

Officials at OTI said they have introduced additional safeguards while conducting a root cause analysis. Normal redundant operations through both emergency centers were restored the following morning, and the city has increased monitoring of 911 recordings and potentially problematic calls.

OTI said the city has also frozen new technology deployments affecting the system. Critical updates must undergo additional executive review while the investigation continues.

“911 is not an ordinary computer system,” Council member Ariola said. “It is the number New Yorkers call on the worst day of their lives.”