Conrad Bain, a veteran stage and film actor who became a star in middle age as the kindly white adoptive father of two young African-American brothers in the TV sitcom "Diff'rent Strokes," has died.

Bain died Monday of natural causes in his hometown of Livermore, Calif., according to his daughter, Jennifer Bain. He was 89. The show debuted on NBC in 1978, an era when television comedies tackled relevant social issues. Bain played wealthy Manhattan widower Philip Drummond, who promised his dying housekeeper he would raise her sons, played by Gary Coleman and Todd Bridges.

TOP 10: TV COMEDY CATCHPHRASES OF ALL TIME

1) AAAAYYYYY !! - FONZIE / HAPPY DAYS

2) WHATCHOO TALKIN' 'BOUT WILLIS ? - ARNOLD JACKSON / DIFF'RENT STROKES

3) YADDA YADDA YADDA - SEINFELD

4) KISS MY GRITS -FLO / ALICE

5) HOW YOU DOIN'? - JOEY / FRIENDS

6) HEY, HEY, HEY, WHAT'S HAPPENING ? - DUANE WAYNE / WHAT'S HAPPENING?

7) DYNO-MITE !! - JJ EVANS / GOOD TIMES

8) I'M COMIN' TO JOIN YOU, ELIZABETH ! - FRED SANFORD / SANFORD & SON

9) UP YOUR NOSE WITH A RUBBER HOSE ! - VINNIE BARBARINO / WELCOME BACK KOTTER

10) ONE OF THESE DAYS...POW ! RIGHT IN THE KISSER ! - RALPH KRAMDEN / THE HONEYMOONERS