Two sections of Auckland's SH16 closed after part of truck blows off

Part of the back of a truck has fallen off along an Auckland motorway this morning, causing havoc on a southbound lane of State Highway 16. 

In an image shared by NZTA, a part of the back of the truck looks to have been blown off. 

As a result, NZTA says the southbound SH16 off-ramp to Patiki Road has been closed.

Police are on the scene, and say the structure will need to be removed safely. They anticipate the removal "may take some time".

One lane of the northwestern motorway directly underneath the overpass has also been closed as a precaution. 

Anyone heading in that direction is advised to exit prior at Te Atatu Road or after at Great North Road until this crash scene can be cleared.

Diversions have been put in place.