A failure of key Comcast equipment in Burlington knocked out cable and cellular service to customers across Whidbey Island and Skagit County for about one and a half hours on Wednesday evening.

A company official confirmed that the problem began shortly before 10 p.m. A device in a power relay system at a signal distribution center broke, and it wasn’t fixed until about 11:30 p.m. Service was restored for most immediately, though an unknown number of customer modems failed to return to service and required visits by technicians the following day.

Comcast records outages by the number of devices, not postal addresses, and estimates are that 13,000 on Whidbey were affected, according to Walter Neary, a company spokesman.

“Every time something like this happens, we look at how we can do things differently to further improve reliability,” wrote Neary in an email to The Record. “We know Xfinity products and services are essential in people’s lives; we regret the inconvenience and are grateful for our customers’ patience.”

The equipment failure was in a facility called a “headend,” a hub where video and Internet signals are assembled, monitored, and sent to and from customers. They’re recognizable by their large dishes, Neary said.

Though the actual failure was with Comcast, the service interruption was widespread. Residents from Clinton to Oak Harbor, and some as far away as Anacortes, reported losing cell service with phone carriers such as Verizon and AT&T. Neary said Thursday many networks are interconnected and that it’s possible that when Comcast’s equipment lost power some customers with other carriers lost service as well.

Whatever the case, the problem also affected I-COM, Island County’s 911 dispatch service. The ability to receive and relay 911 calls was not affected, but certain electronic devices were offline.

According to Systems Administrator John Diamond, I-COM has a fiber network, or ethernet private line, with Comcast that utilizes two pathways. The dual lines offer a redundancy or safety net for I-COM. But when the provider lost its connection at the Burlington facility, both pathways went dark.

“There was about a one-hour down time where we could only wait for them to get it fixed,” Diamond said.

He added that Comcast technicians jumped on the problem right away and were very “efficient.” The service interruption for I-COM was from 9:41 p.m. to 10:39 p.m., Diamond said.

Emergency response agencies were all affected but in different ways. Police, fire department and hospital ambulance units all lost connection to vehicle computers, which provide information about calls to such addresses. IP-based radios were also impacted, but only for South Whidbey Fire/EMS. North end fire agencies and police have redundant systems that shielded them from any radio blackout.

South Whidbey has some as well, but wide areas still received poor reception, said Jon Beck, deputy chief for South Whidbey Fire/EMS. It has to do with the location of redundant transmitters operated by Whidbey Telecom, he said. They weren’t affected but aren’t as numerous, so signals had trouble reaching fire officials in certain areas.

“I live far south on the island, and I really couldn’t hear anything because it was so far away from those transmitters,” Beck said.

The problem was disruptive, but the district was still able to receive 911 calls, Beck added. No calls were missed.