Saw this story earlier today and it has been turning over in the back of my mind ever since.
After his wife got in her car to give chase to some vandals, Stacy Horton followed her in a second car and was only two minutes behind her. One of his sons, named Silva, was also in his wife's station wagon. Arriving at the Whanganui River, north of Wellington, New Zealand, he saw that his wife's car had rolled down the bank and was sinking in the river. He could see that his wife was struggling in the river and having trouble keeping her head above water. At the same time the car was sinking with Silva still inside and was already 3 feet under the surface.
He dived in, swam over to the car and realised that due to the depth of the water he probably couldn't save his son and had to make a decision to either keep trying to swim down in the murky water and try and free Silva or help his wife who was on the verge of drowning. He made the choice to help his wife whom he knew he could save rather than his son whom he had a smaller chance of saving.
Terrible situation to be in.
More here:
Clicky