Police said they had arrested one person in relation to the fatal crash, but were not in a position to confirm charges.
Inquiries were continuing.
Several hours later Whanganui Fire and Emergency was alerted to an early morning blaze at a poultry farm on Papaiti Rd around 12.45am on Sunday.
A Fire and Emergency spokesman said the fire was well-involved and that walls of the building were collapsing when crews arrived.
The spokesman said the shed was approximately 150m by 20m, and housed around 1000 chickens.
At the scene crews were able to stop the fire spreading to a nearby building, but the spokesman said "there's nothing left" of the chicken shed.
Seven fire appliances from Whanganui, Palmerston North, Ratana, Marton and Waverley attended the scene alongside three water tankers and a rural Fire and Emergency unit.
Water from a nearby swimming pool was also used to put out the blaze, and crews at the scene were damping down hotspots by 2.30am.
A specialist Fire and Emergency investigator was working to determine the cause of the fire.