When he was 12, he and his parents were in a boating accident on the lake. They drowned.
5 seconds sound clip from Airwolf (1984) - Shadow of the Hawke (S1.E1) action military drama television series.
You can hear this line at 00:26:26.427 in the Blu-ray version of the TV Series.
Quote context
[...]
- I talked to him last night after you went to sleep.
- Come on. It's too early in the morning, for incriminating looks from the boss.
- Don't get interested in Stringfellow Hawke. There's no future in it for you or any woman.
- Why not?
- When he was 12, he and his parents were in a boating accident on the lake. They drowned.
- Just before he shipped out to Vietnam, he and his girlfriend were in a car crash. She died.
- In Nam, he and his brother went down in the same mission. He got picked up. Sin Jin didn't.
- How's that for some paperback psychology?
- Everyone he loved can't have died.
- There is one who's survived. Up to now, anyway.
[...]