Two casualties have been airlifted to the Southern General Hospital, with a further casualty taken by ambulance to the Dumfries and Galloway Royal Infirmary.
The Northbound carraigeway is closed and will remain so for a considerable period while investigations are carried out. The Southbound carriageway has one lane now re-opened.
More top news
Our autumnal theme continues. But for how long?
A look ahead at the forecast for the Border region.
From Carlisle to the cobbles: Meet Corrie's new bad boy