Car in Hutt river

Was on the bridge by the Melling station and saw a car with its lights on that appeared to be partially submerged in the water, anyone know what happened?

For anyone wanting to know, it's about twenty metres from the nearest bit of rocky ground, and I didn't get a good look but it appeared to be completely surrounded by water except for the driver's side which looked like it was right next to, and parallel to the bank - so doesn't look like a case of someone accidentally forgetting the breaks.