(TNS) — The Pennsylvania Emergency Management Agency (PEMA) announced Tuesday that the preliminary analysis of the 911 system outages more than a week ago determined that the issues were due to a defect in an operating system.

The disruptions are not believed to be the result of a cyber-attack, the press release said.

The outages within the Next-Generation 911 (NG911) system began on mid-afternoon Friday, July 11, and continued into the weekend.

“As soon as the intermittent outages started, our vendors and partner public safety organizations began to investigate the cause and take steps to resolve the issue,” PEMA Executive Deputy Director Jeff Boyle said in the release. “We activated the Emergency Alert System and issued Wireless Emergency Alerts as a precautionary measure to notify everyone in Pennsylvania of the issue and to follow county-based backup plans should they not be able to reach the 911 centers by calling the traditional three-digit phone number.”

Next Generation Core Services (NGCS) are the systems and components used to process and route calls from phones to 911 centers. There are four instances of the NGCS, which are located at two data centers within the NG911 system in Pennsylvania.

The NG911 system in Pennsylvania functions as follows:

• A caller dials “911.”
• The call is transported to one of the data centers for processing by the NGCS, where the NCGS determines the caller’s location and delivers the call to the appropriate Public Safety Answering Point (PSAP, commonly called 911 center).
• The PSAP processes the call and dispatches appropriate emergency services.

If callers couldn’t connect to 911, PEMA advised them during a July 12 news conference to call their county’s emergency call center directly. A list of numbers that go directly to central Pennsylvania 911 call centers can be found at this link.

PEMA used the release to also thank the 61 Public Safety Answering Points (PSAPs, commonly called 911 centers) for all they did during the service disruptions.

A more detailed analysis of this issue and corrective measures are underway, and when complete, additional information that is not security-sensitive will be released.

PEMA suggested that residents save their county 911 center’s 10-digit non-emergency number on their cellphone or write it down in an easily accessible place if a similar situation arises in the future.