There were no other injuries to any of the other vehicle occupants.
The fatality brought the 2016 regional road toll to six.
Cordons were in place shutting the stretch of road off from motorists for the majority of the afternoon, with diversions in place at Te Mahanga Rd and Te Aute Trust Rd.
Emmerson Transport managing director Ian Emmerson confirmed the truck involved was one of theirs.
He said the driver was as good as could be given the situation.
"He's uninjured, but pyschologically he's affected.
"The driver will be supported. Whatever support he needs, we'll give him."
Mr Emmerson said they felt for the families involved.
"You don't wish that upon anyone."
Cars, trucks and school buses were driving on the road yesterday before cordons were set up.
Uniformed students piled out of the buses and waited on the side of the road in 27C heat.
Motorists started doing u-turns as police officers advised of a delay that could be as long as five hours.
A number of trucks had to reverse some 200m back up the road because they were too big to complete a u-turn.