Steven Pinker describes how that went:
> "As a young teenager in proudly peaceable Canada during the romantic 1960s, I was a true believer in Bakunin's anarchism. I laughed off my parents' argument that if the government ever laid down its arms all hell would break loose. Our competing predictions were put to the test at 8:00 a.m. on October 7, 1969, when the Montreal police went on strike. By 11:20 am, the first bank was robbed. By noon, most of the downtown stores were closed because of looting. Within a few more hours, taxi drivers burned down the garage of a limousine service that competed with them for airport customers, a rooftop sniper killed a provincial police officer, rioters broke into several hotels and restaurants, and a doctor slew a burglar in his suburban home. By the end of the day, six banks had been robbed, a hundred shops had been looted, twelve fires had been set, forty carloads of storefront glass had been broken, and three million dollars in property damage had been inflicted, before city authorities had to call in the army and, of course, the Mounties to restore order. This decisive empirical test left my politics in tatters (and offered a foretaste of life as a scientist)."[16]
The idea that this incident demonstrates that any city will go up in flames immediately if the police take the day off is a misreading this specific moment in history.
See: https://en.wikipedia.org/wiki/Murray-Hill_riot
That's not to dispute the idea that cities will generally retain order if police are absent. I imagine it varies wildly from one time and place to another.
> In the first six months of 1969, there were 93 bank robberies in Montreal compared to 48 bank robberies in the first six months of 1968.[5] In January and February 1969, the FLQ staged 10 terrorist bombings in Montreal, and between August 1968 and February 1969, there were 75 bombings linked to the FLQ.[5] In February 1969, the FLQ set off bombs at the Montreal Stock Market (injuring 28 people) and at the offices of the Queen's Printer in Montreal.[5] March 1969 saw the outbreak of violent demonstrations as French-Canadians demanded that McGill University, a traditional bastion of Montreal's English-speaking elite, be transformed into a French-language university, leading to counter-demonstrations by English-Canadians to keep McGill an English language university.[4] The leader of the 'Operation McGill Français' protests was ironically a part-time Marxist political science lecturer from Ontario named Stanley Gray who could barely speak French, but who declared that McGill must become a French-language university to end "Anglo-elitism", rallying support from the Quebec separatist movement.[11] Over two weeks of clashes and protests, McGill was reduced to chaos as Quebec separatists stormed into the meetings of the McGill's Senate and administration chanting such slogans as "Révolution! Vive le Québec socialise! Vive le Québec libre!".[11] The climax of the 'Operation McGill Français' protests occurred on the evening of 28 March 1969 when a 9,000-strong group of Quebec separatists led by Gray tried to storm McGill, and clashed with the police who had been asked by McGill to keep Gray's group off the campus.[11] In September 1969, rioting broke out in the St. Leonard district between Italian-Canadians and French-Canadians with differing opinions of the language issue.[4] Italian immigrant parents had kept their children from school to protest the fact that the language of school instruction was now French instead of English, and on 10 September 1969, a group of 1,500 French-Canadian nationalists attempted to march through St. Leonard's Little Italy district to protest the school boycott.[12] Upon arrival, the marchers were attacked by the Italians, leading to a night of violence on the streets.[13]