John S. Siupinski, 81, of 310 S. 34^th St., was found dead of an apparent heart attack at 4:55 p.m. Monday in his residence by his granddaughter, according to police. He was employed by the Oliver Corp. for 30 years before his retirement in 1956. He was born on Dec. 3, 1891 in Poland, and had lived here since 1921. On Oct. 9, 1921, he married Mary Michalski, who died on Feb. 22, 1961. Surviving are a son Edward of South Bend; three grandchildren, and a sister, Mrs. Mary Kanczuczewski of South Bend. Friends may call from 7 to 9 p.m. today and 2 to 4 and 7 to 9 p.m. Wednesday in Kaniewski and Sons Funeral Home. Services will be held at 9 a.m. Thursday in St. Stanislaus Catholich Church, Rev. Casimir F. Grabarz, C.S.C., pastor, officiating. Burial will be in St. Joseph Cemetery.