If you were a prominent Babylon 5 watcher back in the late 1990s, I am sure you remember the character “Commander Jeffrey Sinclair” played by Michael O’Hare. Unfortunately, Michael O’Hare passed away this past Friday (September 28th, 2012).

Prior to his involvement with the television world, O’Hare was active with the Broadway scene in New York. One of his well-known Broadway appearances was portraying “Col. Nathan Jessup” in A Few Good Men. This role was later played by Jack Nicholson in the movie version of A Few Good Men.

In 1992, O’Hare accepted the role as “Commander Jeffrey Sinclair” in the upcoming Babylon 5 science fiction television series, which then aired in 1993. Although, O’Hare was only with Babylon 5 for one full season, but the character was brought back in season two, and for a very short while in the series’ third season.

Michael O’Hare (born as “Robert Michael O’Hare”) died on September 28th, 2012, after suffering a heart attack and being placed in a coma since September 23rd, 2012. Babylon 5‘s producer J. Michael Straczynski posted the following announcement on his Facebook page:

“I regret that I must convey the sad news that Michael O’Hare passed away today. He suffered a heart attack on Sunday and was in a coma until his passing this afternoon. This is a terrible loss for all B5 fans and everyone involved with the show wishes to convey their condolences to the O’Hare family. He was an amazing man.”

Various fans of Michael O’Hare have been leaving their respects via Twitter: