A Flaxmere driver's family was unable to save him despite their frantic efforts after he texted for help from his car sinking in a Hawke's Bay stream.
Hina Hamahona sent a text message to his family after his car went into the Karamu Stream, near Havelock North, as he was on his way to work about 4.15am on Monday.
The 25-year-old's father and another family member rushed to the scene and tried unsuccessfully to pull Mr Hamahona out of the car.
Police say by the time emergency services were called and arrived, the car was fully submerged and Mr Hamahona was dead.
It's not yet known whether he died as a result of his injuries from the crash or by drowning.
The Serious Crash Unit is investigating.
