At around 07:00, the deer on the expansive lawns of the French colonial-era palace were frightened off as Quốc and Cử—flying American-built A-1 Skyraiders (A1H/AD-6 variant) single-seater ground attack planes—flew low over their target to inspect the ruling family's residence. On their second run, they dropped bombs and napalm before firing rockets and strafing the presidential compound with machine-gun fire. The two continued their runs for 30 minutes before units loyal to the president arrived and launched a counter-attack.
Taking advantage of poor weather and low cloud cover, the two pilots circled the palace at altitudes of around 150 m (490 ft), periodically diving out of the clouds to re-attack before darting back into them. The airstrike caught the Saigon garrison off guard and, in the confusion, they were unable to determine whether the aircraft were acting alone or with ground forces. Loyalist tanks and armoured personnel carriers rushed to their battle stations and anti-aircraft batteries opened fire, nearly hitting the loyalist aircraft from Bien Hoa Air Base in pursuit of the two rebel planes. Two tanks and a number of jeeps armed with 50-calibre machine guns patrolled the smoke-filled streets as a precaution.
The first 500 lb (230 kg) bomb penetrated a room in the western wing where Diệm was reading a biography of George Washington. The bomb failed to detonate, which gave Diệm enough time to seek shelter in a cellar in the eastern wing. He was joined there by his elder brother Archbishop Pierre Martin Ngô Đình Thục, younger brother Ngô Đình Nhu, Madame Nhu—who sustained an arm fracture while running toward the cellar—and their children.