WORCESTER, Mass. — A preliminary investigation into Tuesday’s 911 outage finds it was the result of a firewall.

The state 911 Department said it's a safety feature to protect against cyberattacks and hacking. The outage lasted about two hours until service was fully restored.

The Executive Office of Public Safety said the firewall prevented calls from getting to 911 dispatch centers.

The 911 Department said they moved immediately to address the disruption, and discussed the situation with its 911 vendor Comtech, while also alerting local law enforcement and connecting with MEMA to send a statewide emergency alert.

"It was a problem involving software, actually a firewall protection system that was actually too protective and ended up blocking calls from going through for a period of about two hours” Gov. Maura Healey said. “I'm not aware of any emergencies or issues in terms of people negatively impacted as a result of that, but obviously, for me, it's about finding out what happened, getting the answers and making sure it never happens again. And that's what we're doing."

Comtech has advised State 911 to apply a technical solution to ensure this doesn't happen again.