Tens of thousands of people in Derbyshire and parts of Staffordshire are thought to be without a phone line following a fire at the BT exchange in Derby.
The problem in Ashbourne is currently affecting some homes, businesses and also schools such as St Oswald's C of E Infant School and Ashbourne Town Hall.
The fire, which broke out in the early hours of this morning (7th October), was on the first floor of the exchange.
A BT spokesman told local reporters said: "One thing that is clear is it has affected tens of thousands of people in and around the Derby area. We do not yet know specifically which areas have been affected but hopefully this will become clear throughout the investigation."
No-one was in the building at the time of the fire.
Commercial buildings, non-domestic and multi-occupancy premises in England and Wales are already forced to undertake a 'suitable and sufficient' fire risk assessment carried out under the Regulatory Reform (Fire Safety) Order 2005.
While the overwhelming majority of premises do this, if the assessment is thought to have been carried out to an insufficient extent, the Responsible Person can face an unlimited fine or up to two years in prison.