A driver has died after suffering a medical event before crashing near the Waterview Tunnel in Auckland.
Road authorities have re-opened all lanes just outside of the tunnel, heading towards Mt Roskill, after a crash caused delays about 7.30am.
Emergency services were called to the scene after reports of a crash. A police spokeswoman confirmed a person suffered a medical event and was initially said to be in a serious condition.
However, the person later died at the scene, police confirmed.
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Despite the medical condition, the Serious Crash Unit was called to the site to investigate the circumstances of the crash and subsequent death all the same.
It is understood the driver crashed into the barrier before coming to a stop. They did not hit any other vehicles, police said.
The incident caused huge delays in and around the area, as emergency services worked at the scene for just over three hours - reducing that part of State Highway 20 to one lane.
All lanes were reopened by about 11am.
Motorists were told to delay all travel, find an alternative route or expect delays.
"Long delays building through the southbound Waterview Tunnel.
"Please delay your journey or use SH1 to travel south this morning," the NZ Transport Agency said just after 8am.
St John said it had been called to a series of car crashes near the Maioro Rd side of the tunnel between about 7.20am and 7.36am.
As a result, paramedics had treated a total of four people with minor injuries. None of those people needed hospital treatment.
At least two crashes just after 7.30am
The congestion comes after crashes on both sides of the tunnel were reported just after 7.30am.
Shortly before 8am, the northbound crash was completely cleared and all lanes in the tunnel were open again.
Police confirmed that that was a nose-to-tail crash that resulted in no injuries.
Meanwhile, a breakdown also blocked a lane near the Spaghetti Junction heading south from SH16.
The far left lane was blocked and motorists were told to merge to pass with extra care and to expect some delays this morning.