Originally Lucas hired Leigh Brackett(The Big Sleep, Rio Bravo) to write the screenplay of The Empire Strikes Back but she died of cancer right after turning in her first draft(PDF here). Even though hardly any of it was used in the finished film, Lucas still gave her a co-writing screen credit with her replacement, Lawrence Kasdan, because he liked her.
When Return of the Jedi director Richard Marquand unexpectedly died of a heart attack at the age of 49 in 1987, Lucas flew to England to attend his funeral.
In 2005 during the AFI Life Achievement Award for Lucas, the main trio of the original Star Wars trilogy, Mark Hamill, Carrie Fisher and Harrison Ford were together onstage for the first time in years as John Williams' "medal ceremony" music from A New Hope played. An overcome Lucas stood from his seat in the dais and applauded and the whole room joined in.