A network failure which meant that Hull residents could not dial 999 calls for four hours has cost the outfit responsible £900,000.

KCOM was investigated by Ofcom after residents in the Hull area could not connect 999 calls between around 21:58 on 27 December and 1:43 on the following day.

The supplier provides the phone and broadband network for most of the Hull area, was reprimanded by Ofcom after the regulatory body found “a serious weakness” in the firm’s emergency call services.

Gaucho Rasmussen, Ofcom’s enforcement and investigations director, said: “Ofcom rules mean that people must be able to call the emergency services around the clock.

“Any failure to connect 999 calls is extremely serious. Today’s fine serves as a clear warning to the telecoms industry that it must prioritise access to the emergency services, no matter what the circumstances.”

Storm Eva in 2015 on the day of the incident meant that a BT telephone exchange in York, which connected calls from KCOM’s network to the emergency services through BT, had flooded. KCOM had contingency plans in place, but these relied on the same exchange being operational.

There were more than 74 calls to the emergency services, from 34 telephone numbers which failed to connect through the four-hour period.

Ofcom acknowledged that KCOM had addressed the problem within two hours of discovering it, but said the firm still warranted a fine that “reflects the seriousness of the breach and its impact on public health and safety”.

In a statement sent to CRN KCOM said: “We recognise the critical importance of providing our customers with uninterrupted access to emergency call services and take that responsibility extremely seriously.

“During Storm Eva in 2015 the loss of our 999 service was a result of a single point of failure in another operator’s exchange in York.

“Our emergency call services are managed through long-standing external outsourcing arrangements. In establishing them, we sought to ensure diverse and resilient routing which Ofcom has acknowledged in its findings.

“We’re very sorry this happened and immediately after the incident we ensured steps were taken to remove this network vulnerability.”