Cyclone Gabrielle hit New Zealand's North Island, particularly the Hawkes Bay region, causing widespread flooding and damage. The cyclone had wind speeds of up to 159 km/h (99 mph) and caused 11 deaths, and at least 10,000 people were displaced.  The damage caused by the cyclone is forecast to cost NZD$13.5bn ($8.4bn; £6.9bn), similar to the financial impact of the Christchurch earthquake in 2011 - the costliest natural disaster in New Zealand's history.  The cyclone has triggered a national debate about climate change and whether vulnerable homes should be rebuilt or written off.  As of 2.30 pm on Thursday, 3,455 people had been registered by police as “uncontactable”, with some likely to be multiple reports for the same person. The prime minister, Chris Hipkins, warned that there were some people for whom the police held “grave concerns”.  Fresh evacuation orders were issued on Thursday morning for residents of central Hawke’s Bay, with those around Drumpeel Road told to “leave immediately”. Communication to the worst-affected areas remained difficult, with authorities relying on the Starlink satellite communications service from Elon Musk’s Space X to provide internet in some areas.  About 102,000 households were still without power across the North Island as of Thursday afternoon, down from about 225,000 on Tuesday morning.  The damage from the cyclone is extensive, with homes partly immersed in silt and mud, or shifted off their foundations. Urban Search and Rescue was still rescuing people from their homes in Hawke’s Bay, and there are a large number of people unaccounted for.  The prime minister, Chris Hipkins, described the damage as “extensive”, with basics like food and clean water still needed. He described the cyclone as an event on the scale of the Christchurch earthquake in 2011.  New Zealand requested Australia’s help for disaster response on Thursday morning. Speaking earlier in the day, the prime minister said New Zealand would be forced to re-evaluate and remake its infrastructure in response to extreme weather events.  Clean-up efforts are underway in Hawke's Bay, with huge areas buried beneath mud and debris. Satellite data has revealed just how hard Cyclone Gabrielle hit Hawke’s Bay.   The Wairoa River burst its banks and caused severe flooding in northern Hawke's Bay. Many people were trapped on roofs, and helicopters were used to rescue hundreds of them.  MetService issued a severe thunderstorm warning for Thursday afternoon for areas including the Bay of Plenty, Gisborne and the Hawke’s Bay region. The warning was for “very unstable conditions” including “heavy rain and hail”.  Rainfall of this intensity can cause surface and/or flash flooding, especially about low-lying areas.  Residents of the worst-hit areas are faced with the challenge of cleaning up after the cyclone, with many homes destroyed or severely damaged.   The cyclone has prompted discussions about climate change and the need to evaluate and rebuild infrastructure to become more resilient to extreme weather events.