Mack Wesley Cantrell, 46, a security guard who was wounded by a shotgun blast when Hanafi Muslims took over the fifth floor of the District Building on March 9, died Monday night at Washington Hospital Center. Death was attributed to a massive coronary thrombosis.

A spokesperson for the hospital said Mr. Cantrell, who had suffered from a heart ailment, was admitted there 15 days ago after he was striken at work and that he was in the cardiac intensive-care unit when he died.

Mr. Cantrell was wounded in the onslaught that killed Maurice Williams, a reporter foc WHUR-FM, and wounded City Council member Marion Barry.

Doctors reported that a bullet struck Mr. Cantrell under his eye, hit his skull and tunneled around the skin and out the back.

The accused Hanafi Muslims are now on trial in Superior Court. Mr. Cantrell had not yet testified.

Born in Knoxville, Tenn., he came to Washington as a boy and graduated from Armstrong Vocational High School.

Mr. Cantrell had worked for the Veterans Administration, the Government Printing Office as a press helper, and in landscaping work.

He became a security guard with the city's Department of General Services on Feb. 21, 1971.

He is survived by his wife, Delores LaVerne Cantrell, of the home in Washington; his mother, Samantha Cantrell, and his father, Purcell Cantrell, both of Knoxville; a brother, Emory, of New York City, four stepdaughters, Christine Rodgers, of Washington, and Yvonne, Cassandra and Jonne Rodgers, all of the home, and a grandchild.