By JAY MALLIN
Miami News Special Writer

     A plot to kill Fidel Castro failed because a bazooka did not fire. This was revealed by a Cuban underground leader now in Miami. In October of 1960 Antonio Veciana, 33, rented a three-bedroom apartment (No. 8-A) at Residencial Misiones No. 29 in downtown Havana. Veciana was a bank official.
     But Veciana had another responsibility: He also was head of the action and sabotage section of the Revolutionary Movement of the People, one of the major anti-Castro clandestine movements.
     Veciana wanted the apartment for a very special reason. It provided an unobstructed view of the north terrace of the Presidential Palace, about 120 yards away.
     Veciana moved his mother-in-law into the apartment and he set about preparing his plans. He and hid co-conspirators planned to assassinate Castro. But hitches, government vigilance and a lack of proper weapons caused endless delays.

SPEECH ON TERRACE

     Not until October of this year was the plan ready to be carried out. Cuban President Osvaldo Dorticos had been touring the Iron Curtain countries, and he was due back in Cuba Oct. 5. Castro would greet him, and they would address a welcoming rally from the north terrace.
     At 11 p.m. on Oct. 4 Veciana entered Apartment 8-A with his mother-in-law. He carried a gift-wrapped package from which could be seen protruding a lamp.
     Although the area around the palace is heavily patrolled, none of the guards was suspicious of the package and no one stopped Veciana.
     But inside the package was a bazooka with a range in excess of the 120 yards between the apartment and the terrace, where Castro would be standing.
     The next day the welcoming rally was held as scheduled. But the assassination attempt did not take place. The bazooka failed to fire.