StarTrek.com has the obituary on the passing of James Doohan:
James Doohan, the beloved actor who portrayed engineer “Montgomery Scott” in the original Star Trek and six movies, passed away at his home in Redmond, Washington this morning. He was 85. Doohan died in his sleep at 5:30 a.m. local time with his wife of 28 years, Wende, at his side. According to Doohan’s Los Angeles agent and longtime friend Steve Stevens, the cause of death was pneumonia and Alzheimer’s disease.
Doohan’s Scotty has always been my favorite Trek character, his wit and wisdom often out-shining that of Kirk and Spock. He will be greatly missed.
Doohan served in World War II, and was wounded in action during the Normandy Invasion on D-Day.