A fire investigator is on the scene trying to work out the cause of the fire.
St John took one person to Auckland City Hospital.
Suspicious fire in Henderson
Meanwhile, a suspicious fire has gutted an abandoned home in Henderson this afternoon.
Five fire trucks were called to the blaze on Edmonton Rd about 2.30pm.
A Fire and Emergency NZ spokesman told the Herald the house was well involved in flames when crews arrived.
The fire started in the basement of the apparently abandoned house, the spokesman said.
Firefighters were still trying to extinguish the blaze at 3pm but it had been contained to the house.
Fire investigators have been called to the address as Fenz had reason to believe the cause was suspicious, he said.
Rugby clubrooms destroyed by fire earlier this morning
Emergency services responded to another fire in Mt Albert earlier this morning when the Marist Saints rugby clubrooms were destroyed.
Authorities responded to reports of the blaze about 3.30am.
Auckland Rugby League chief executive Rebecca Russell said the fire was devastating for the community.
She said they are working with Fenz to investigate the cause of the fire and could not comment further.
Visibly upset members of the Marist Rugby League Club gathered on the field in front of the gutted remains of their club building this morning.
Fenz assistant commander Chris Delfos said the clubrooms on Range View Rd in Mt Albert were well involved when they arrived.
Club member Rua Kimiora said everyone was upset and devastated, “especially because this building has been here for over 100 years”.
Multiple people called emergency services and crews arrived quickly from Avondale and then other surrounding stations as they called in assistance.
The two-storey, 15m by 30m structure is in Murray Halberg Park. The fire had gone to a second alarm, which meant about eight appliances had been called.
A police spokesperson said no injuries were reported.
Raphael Franks is an Auckland-based reporter who covers breaking news. He joined the Herald as a Te Rito cadet in 2022.