Hundreds prepare to evacuate as Northland tsunami sirens go of accidentally 16 Mar, 2021 04:00 PM 3 minutes to read Thousands evacuated to higher ground during the March 5 tsunami evacuation in Whangārei, but on Monday night the sirens went off accidentally after a technical glitch. Photo / Mike Dinsdale By Mike Dinsdale A tsunami siren false alarm caused widespread worry in parts of Northland with Northpower - which runs the siren network - apologising and vowing to do everything to ensure it doesn't happen again. Northpower has apologised to people in the Kaipara and Whangārei Districts after an unnamed technical issue in its control systems caused the coastal tsunami sirens to activate from 8.21pm to 8.24pm on Monday night.