And in Auckland, an 8-year-old boy tried to kill himself because school was "too hard".
He was found with external marks and apparently recovering quickly from brief unconsciousness in the grounds of Cornwall Park District School.
But his parents told the Herald they were furious the school did not call 111 for an ambulance.
This week a Hawke's Bay clinical psychologist met the administrators of the dead girls' social media tribute pages.
Luke Rowe, a doctor with clinical support group Te Taiwhenua o Heretaunga, said tapping into sites such as Facebook, Twitter and Ask.fm was a powerful tool that parents, caregivers and professionals should use.
"We have teens talking about these things on social media sites which is very powerful - it can be good and bad."
Rowe wants to use the tribute pages as a way to stop further deaths by letting troubled teens know what services are available to them.
"We have met administrators and talked about getting phone numbers of support services on these pages so teens know where to go if they need help."
Rowe had a five-step checklist for parents, teachers and caregivers of at-risk teenagers.
Korero: encourage talk on feelings about suicide and how to prevent it;
Seek professional advice from GPs and counsellors for your child;
Understand what is going on in their life, such as drugs, bullying and relationships;
Remove risk for troubled teens by minimising the opportunity for them to self harm
Give hope. Put a plan in place, tell them they can get through and help them do it.
Hastings deputy mayor Cynthia Bowers said teenagers throughout New Zealand needed to know what people were available in the community for them to talk to when troubled.
"We have to ensure there are people on the ground that young people can talk to instead of taking that drastic and awful step of taking their own life," Bowers said.
Bowers went to prizegiving at Flaxmere College on Friday and said the fact the school had lost two students to sudden deaths recently was on everyone's minds.
"These students had all achieved so well, but couldn't help but be sad for the ones that were no longer there."
Where to get help
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (4pm to 6pm weekdays)
• Whatsup: 0800 942 8787 (noon to midnight)
• The Word
• Depression helpline: 0800 111 757 (24-hour service)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.