The heavily damaged Sri Ayudhya listing before it sank on 1 July 1951
The Manhattan Rebellion was a failed coup attempt by officers of the Royal Thai Navy against the government of Prime Minister Plaek Pibulsonggram (Phibun) on 29–30 June 1951. A group of junior naval officers seized Phibun at gunpoint while he was attending the transfer ceremony of the US Navy dredge Manhattan to the Thai navy at Ratchaworadit Pier on the Chao Phraya River in Bangkok. Phibun was forcibly taken aboard the Thai navy flagship HTMS Sri Ayudhya and held hostage. General stations were called, and the ship began to make way downstream towards the Naval Ordnance Department in Bang Na.
However, the coup plotters failed to secure the opening of the Memorial Bridge, so the ship could not continue downstream. Fighting quickly ensued, and the naval units that sided with the rebels became heavily outnumbered by the army, police, and air forces, who were loyal to the government. Fighting subsided during the night of 29 June, but resumed and intensified early the next morning. Sri Ayudhya joined the fight, but its engines were soon disabled and the ship became dead in the water in front of Wichaiprasit Fort. It was heavily fired upon from the eastern bank by guns and mortars, and, by afternoon, was also bombarded by AT-6 trainer planes. Heavy fires broke out, and the order was given to abandon ship. Phibun had to swim ashore along with the sailors, but was uninjured. The fires continued throughout the night and into the next day, when fighting ceased. The heavily damaged Sri Ayudhya finally sank on the night of 1 July.The struggle led to the deaths of 17 military personnel, eight police officers, and 103 civilians. More than 500 people were wounded. Property damage amounted to 15 million baht and the loss of the navy's most powerful warship.:p.41
The wreck of Sri Ayudhya was later salvaged for scrap, as it had become a navigational hazard. The ship was officially struck from the naval register on 8 October 1959 in Ministerial Order 350/21315.