An air force officer arrested for taking part in a coup attempt was fatally wounded by guards today as he tried to scale a wall of his military prison, the armed forces said. Lt. Col. Francisco Baula, accused in a 1987 attempted coup that left 53 people dead and more than 300 wounded, died at a military hospital about nine hours after his bid to escape from the suburban Camp Crame stockade, military officials said. Last year's military uprising, led by former Lt. Col. Gregorio ``Gringo'' Honasan, was the most serious effort to oust the government of President Corazon Aquino. She came to power in February 1986 after a military-civilian uprising ousted President Ferdinand Marcos, who fled to Hawaii. Maj. Gen. Ramon Montano, commander of the Philippine Constabulary, said Baula was shot and wounded three times after he refused to halt and ignored warning shots. The stockade is located at the constabulary. Montano said Baula slipped into a dark corner of the stockade shortly after midnight and tried to climb over the wall with a makeshift ladder. Percival Adiong, the Camp Crame commandant, said Baula used wooden slats and the two frames of his double-decker bed to make the ladder. ``Our investigation shows that there were no others who tried to help him,'' Montano said. Baula was arrested Oct. 3 with two other military men sought in connection with the coup attempt on Aug. 28, 1987. Honasan remains at large. He was jailed last December but escaped from a prison ship in Manila Bay the following April.