The parents of a critically injured Boston University student have arrived at Waikato Hospital where their daughter remains in intensive care.

Meg Theriault, 21, suffered a serious head injury, broken right arm and grazing to her body when the car she was a passenger in, crashed near Turangi on Saturday morning fatally injuring three international students.

In a statement released this morning, Todd and Deb Theriault of Boston, Massachusetts said they were pleased their daughter was "in a place where there is so much love, care and attention''.

"We know she is in good hands and as we were travelling to New Zealand, we knew that the medical staff in the intensive care unit were doing all they could for her,'' they said.

Miss Theriault is a business management student at Boston University who has been working as an intern in Sydney since mid January. She came to New Zealand a fortnight ago for a holiday and was due to return to America later this month.

Her parents offered their "thoughts and prayers for the families who have lost loved ones in the accident''.

"We know what they are going through and what it’s like to receive such devastating news from the other side of the world,'' they said.

They describe their daughter as a "fit and stubborn young woman'' and said they would remain in Hamilton "for as long as it takes''.

The Theriaults thanked everyone who helped at Saturday's scene. 

"I understand there were people there who did all they could to help Meg and the others in the accident. The emergency services people and the police did an outstanding job given the nature of the accident.''

"Our special thanks to all those people in Boston and around the US who are praying for our daughter. It all helps.”

A Boston University website reported that Stephen Houseman and Emily Melton had been treated and released from Taupo Hospital while two other students Alys McAlpine and Kathy Moldawer remain in a stable condition in Rotorua Hospital.

- © Fairfax NZ News