Nightly News | September 30, 2011
>>> in the mountains north of los angeles , the winding roads can be very treacherous. last week, a dlooiriver went off one of those roads and into a deep ravi ravine. what happened next is a story of love and survival.
>> reporter: it's a survival story along a winding mountain road with an incredible twist.
>> i strained down there and someone said help.
>> reporter: david lavau was missing. his family knew something must be wrong so they contacted authorities and then --
>> if anyone can find our dad it's us.
>> reporter: like detectives they checked his facebook and checked his cell and credit card records.
>> we were able to ping the cell phone towers.
>> reporter: which led them to a remote road.
>> they stopped at every ravine. there are a lot of them. here, they got lucky and heard their dad shouting up to them from some 200 feet below.
>> oh, my god. my dpad. i ran up, looked down and saw my dad's car.
>> reporter: lavau survived the crash and stayed alive for six days.
>> i said, how did you make it? he said, i drank the water in the river and ate leaves and bugs.
>> reporter: needle in a hay stack?
>> that's a good description.
>> reporter: good police work.
>> they did a great job.
>> reporter: and they helped solve another mystery. next to lavau's blue car , a silver one from an earlier accident with a victim dead and still inside.
>> my dad crashed there, survived and now the family that's been wanting their father to know what happened and now they have peace. i wish it was better peace. i'm sorry for that.
>> reporter: as for the lavaus, dad, david, is expected to make a full recovery thanks to the family that refused to give up.
>> we found him. no one else did. we did.
>> reporter: kristen dahlgren, nbc news, california.