Her mother, father and two other men between the ages of 22 and 28, suffered multiple injuries including a dislocated hip, arm and leg fractures, lacerations and abdominal trauma. All were intoxicated at the time and have been listed as stable at Hawke's Bay Hospital.
"There were five of them on the bike, it's unbelievable, really," Mr Gaddum said.
"The woman had lacerations to the side of her face and was pretty hysterical, she was quite badly hurt but she was more concerned for her daughter [who] must have had some impact to her face, because it was all blown up," he said.
As an experienced member of the Waimarama rural fire force, Mr Gaddum was quick to assess the situation and call for help.
"I went into the house and dialled 111; the fire brigade are just at the bottom of the hill, so they got here pretty fast. The ambulance and helicopter came later."
A 28-year-old man with multiple fractures, to his leg and the 6-year-old were airlifted to Hawke's Bay Hospital by Lowe Corporation Rescue Helicopter, while the three remaining adult patients were transported by ambulance.
The young girl was later transferred to Starship, because of the severity of her injuries.
It is believed the accident victims were all from Hawke's Bay and some were Waimarama locals.
At the Okaihau Rd scene yesterday morning, cans of pre-mix cola and bourbon and a pair of sunglasses lay strewn in the grass, while the quad bike sat at the bottom of a bank, butted up against a tennis court fence having veered off the road on a sweeping bend.
Police continued their investigations in the light of day, but had not yet determined who was driving or whether speed was a factor.
Charges were also likely but had not been laid, Senior Constable Alan Daly said.
"Obviously someone's been injured, so it might be careless driving causing injury. That's the kind of charge we would look at depending on how it all pans out," Mr Daly said.
Blood samples had been taken from all four adults to determine alcohol levels, and would be used to prosecute the driver of the vehicle.
Senior Sergeant Luke Shadbolt condemned the actions of the adults involved, who, "should have known better".
"The dangers of quad bikes are well known and documented, but to have it overloaded and be driving under the influence of alcohol; it's an act of stupidity and negligence.
"It was certainly a chaotic scene and the child was obviously distressed; as my staff relayed the situation to me you could hear her screaming and crying in the background. These are things that we have to attend, but they are infinitely avoidable."