AT&T agreed to pay a fine of $5.25 million as part of a settlement with the US Federal Communications Commission (FCC) related to network outages which prevented thousands of customers from reaching emergency assistance in 2017.

The fine resulted from an investigation into two outages of 911 service on AT&T’s VoLTE network in 2017, one in March and the second in May. During the five hour outage in March, nearly 12,600 callers were unable to get through to emergency services. An additional 2,600 callers failed to connect with assistance during a nearly hour-long outage in May.

FCC officials found both outages were preventable, stemming from planned network changes which inadvertently interfered with 911 call routing.

Commission Chairman Ajit Pai previously called the outages “unacceptable”.

As part of the deal, AT&T also agreed to adopt a risk management plan aimed at preventing and reducing the impact of future outages, and providing timely notification of outages to 911 call answering centres. The operator will file regular compliance reports with the FCC.