They most probably were not brothers, I was wondering if Frank was Harry's Father? Uncle?
No, they are not related.
Frank Morgan died on September 18, 1949 at the age of 59.
Frank Morgan was born on June 1, 1890.
Harry Morgan, the American actor, died peacefully in his sleep at 3:00 a.m. on December 7, 2011, at the age of 96.His son Charles said he had been recently treated for pneumonia.