A bold experiment in prison reform went horribly wrong on the island of Pulau Senang, Singapore’s much-acclaimed prison without bars, when between 70 and 90 prisoners – about a quarter of the detainees – triggered a bloody riot.

Until that moment in July 1963, the island was a sort of prison Garden of Eden. Over the previous few years prisoners had constructed an attractive, busy settlement in which they were free to move about at will. The superintendent, Daniel Dutton, believed he could reform the inmates, and abolished the use of arms to police them.

But when the riot began the prisoners specifically targeted Mr. Dutton, hacking him to death and gouging out his eyes. Two other officers were killed, and a number of the staff, along with some other prisoners who didn’t join the riot, were injured.

When police were called to the island none of the rioters offered any resistance. Some were even playing guitars and singing songs.

In November 1963, a huge dock was specially constructed in a Singapore court to hold 58 of the prisoners accused of the three murders. Almost all of them were hardened criminals or Chinese secret society members, who were detained without trial under a security act.

At the 64-day trial it emerged that things weren’t quiet so idyllic in Pulau Senang Prison. Prisoners felt they had no hope of release, because the parole system was biased and unpredictable. They often had to work late and they accused the prison guards of corruption.

The jury of seven men found 18 of the accused guilty of murder. They were sentenced to death and hanged at Changi Prison on Friday, October 29th, 1965, in batches of three at a time.

Another 18 were found guilty of rioting with deadly weapons and sentenced to three years; 11 were guilty of rioting and sentenced to two years, and the remainder were acquitted.