Ernie Hudson was shaken as he met our photog outside a terminal at LAX, having just learned his "Ghostbusters" co-star Harold Ramis had died.

Ernie is emotional and what he says is clearly heartfelt. He humbly confesses he probably wouldn't have had a career without Ramis ... and then goes on to explain why he was such a legend in the movie business.

And on a sad note ... Hudson says any possibility of a new "Ghostbusters" movie is now out of the question.