Irwin Allen, 75, producer of big-budget disaster epics, yesterday of a heart attack in Santa Monica, Calif. He had been in failing health for the past few months. Mr. Allen earned the nickname "Master of Disaster" because of his disaster hits, including "The Poseidon Adventure" in 1972, "The Towering Inferno" in 1974 and "The Swarm" in 1978. "The Towering Inferno" received an Academy Award nomination for best picture. "No, I'm not going to run out of disasters," he said in a 1977 interview. "Pick up the daily newspaper, which is my best source for crisis stories, and you'll find 10 or 15 every day."