A former Civil Defence planner is questioning why his father and other coastal residents were not evacuated from their homes sooner.
Joel Benjamin was concerned his Westshore-based father was still in his home when he rang half an hour after a 7.5-magnitude earthquake rattled much of the country.
Mr Benjamin wanted to know why Hawke's Bay Civil Defence failed to sound warning sirens or evacuate residents in low-lying, high-risk coastal areas of Napier, such as Westshore and Ahuriri, which were both in the "red zone", when a decision was made to warn and evacuate residents at Haumoana and Te Awanga.
He was not the only person critical of Civil Defence, with many taking to Facebook to voice their concern.
Hawke's Bay Civil Defence emergency management group controller Ian Macdonald said he had expected some community questions over their decision not to set off the major sirens. But he said the information Civil Defence had received and its emergency tsunami model had showed them it a big wave wasn't likely to hit.
"We do not have specific tsunami warning sirens, only a mass public alerting system, which connects Taradale, Te Awanga, Napier City, Ahuriri and Westshore."
"This meant if we activated the sirens the whole of the city would be affected right from Westshore to Te Awanga. We cannot just choose to activate one alarm at one spot."
Mr Macdonald said the alarms heard in Te Awanga and Haumoana were from the fire station and stingers, which were vehicles carrying mobile sirens.
"Ministry of Civil Defence emergency management doesn't support use of the major sirens, as it is problematic. We thought about the safety and it is dangerous if people start jumping in their cars and heading inland, especially at 1am."
"A mass movement of people in the early morning can create dangers of its own." Mr Macdonald said all residents who were in the red zone had been evacuated by police or members of the Civil Defence.
"There are 15 residential properties in the red zone at Westshore and all of these people were evacuated, there is no one in the red zone at Ahuriri."
Research was done last year by the Civil Defence emergency team to decipher the trouble areas for when tsunamis hit.
"We use a mathematical model and Westshore and Ahuriri are higher, whereas Te Awanga and Haumoana are much lower. It depends on the run up - the shape of the seabed and the beach and the steepness."
Mr Macdonald said he was happy with how the evacuation process went and was comfortable with what the team achieved.
"We will have a debrief and go over everything but we are happy with the decisions that were made."
He said if they had activated all of the alarms it would have caused a lot more problems than necessary.