O'Hare is notable to me because he starred in the lead role during the first season of my favorite childhood television show, Babylon 5, as Commander Jeffrey Sinclair. Sadly, the Babylon 5 cast has suffered a number of deaths in the past ten years, with Richard Biggs, Andreas Katsulas, and Jeff Conaway all having died; in addition, a main actor from the series' pilot, Johnny Sekka, died in 2006; and a prominent guess actor, Tim Choate, was killed in traffic accident in 2004.
Besides Babylon 5, O'Hare was a stage actor with experience on Broadway. His part in the play Shades of Brown earned him a nomination for an AUDELCO Award for Best Actor; the AUDELCOs celebrate African-American excellence in theater, and O'Hare was the first white actor to be nominated. His other on-screen credits include L.A. Law and Law & Order.
A short memorial video has been uploaded to YouTube. It contains a fitting line of his from Babylon 5 and has a farewell message at the end:
May 6 1952 - September 28 2012