NEW YORK (AP) — People who were stricken with cancer after being exposed to the toxic ash that exploded over Manhattan when the World Trade Center collapsed would qualify for free treatment of the disease and potentially hefty compensation payments under a rule proposed Friday by federal health officials.

After months of study, the National Institute for Occupational Safety and Health said in an administrative filing that it favored a major expansion of an existing $4.3 billion 9/11 health program to include people with 50 types of cancer, covering 14 broad categories of the disease.