From the Merc website:
THE Pinnacle Rd on Mt Wellington has been blocked by a boulder that fell near the roadside.
Police closed the road at the Springs about 5pm today because the massive rock, estimated to weigh up to 40 tonnes, was perched precariously by the road.
A Hobart City Council spokesman said a member of the public alerted authorities after hearing the rock crash through the bushes.
The road will remain closed tomorrow morning while geologists assess the danger posed by the rock.