Ambulance chiefs plan a shake-up of contact centres in the north-east of England, claiming they would not stand up under a terrorist attack.
The North East Ambulance Service NHS Trust (NEAS) says the move will involve closing an existing 999 call centre on Teesside and moving it to Tyneside.
Currently, centres in Newcastle and Middlesbrough have technical links and operate as a single virtual centre.
But bosses say this model could fail under an attack or major incident.
A study has recommended there should be two independent contact centres for the North East.
The ambulance service now plans to keep its existing centre in Newcastle and create a second centre in Hebburn on South Tyneside.
Colin Cessford, director of strategy and clinical standards, said: "The review of our current set-up showed that we needed to improve our resilience in the event of a catastrophe.
"It will have no impact on the location of ambulance stations or the ambulance crews who currently respond to the calls we receive.
"Terrorist attack and natural disasters in recent times has highlighted the need for us to ensure that we can maintain a continuous and uninterrupted service for the whole region."