At Occupy Burlington in Vermont, it happened after a 35-year-old army veteran shot himself in the head. At Occupy Oakland in California, it was after rival gangs clashed, leaving one man dead.
Evictions of Occupy Wall Street protests are sweeping away encampments from New York's Zuccotti Park to St. Paul's Cathedral in London, leading some activists to accuse authorities of co-ordinating efforts to throw them out. Officials cite concerns over public safety as the motivation, saying the camps have become dangerous and in some cases deadly.
As protesters scramble for injunctions to avoid eviction, however, analysts say shutting down the camps could prove a blessing for the broader Occupy movement. The encampments, they argue, were bound to fizzle out with the onset of winter. Evictions have given the movement a much-needed jolt, they say.
"If the authorities had just left the encampments carry on, it might have worked in their favour," argues Laurel Weldon, a professor of political science at Purdue University and author of When Protest Makes Policy. "History shows when states crack down on movements it tends to generate more support for them."
Dr. Weldon dismisses conspiracy theories that suggest city mayors worked in concert. She argues the encampments had already begun to stagnate. Supporters had grown tired and bored while the patience of local residents surrounding various camps had begun to wear thin.
The timing of the evictions couldn't have been better for the movement, Dr. Weldon says. The civil-rights movement, the women's movement and even the Tea Party had to move off the streets before they could mature into something more meaningful, she maintains.
Bob Kiss, mayor of Burlington, Vt., said timing had little to do with his decision to shut down the Occupy camp in his city. After the army veteran's suicide the 16-day-old camp had become "a crime scene" he explained.
"It was clear there were guns in the encampment," Mr. Kiss said. "We could no longer protect the people."
This week, Jean Quan, mayor of Oakland, told the BBC that she spoke with officials from other cities over the phone before launching a raid on Monday morning that shut the Occupy camp down.
"I was recently on a conference call with 18 cities across the country who had the same situation," she said.
"What had started as a political movement and a political encampment ended up being an encampment that was no longer in control of the people who started them," she continued.
Other analysts say the strategy of setting up encampments was a bad fit with the goals of the protest, highlighting social and economic inequality.
T.V. Reed, a professor at Washington State University and author of The Art of Protest, argues protest camps are successful only if the land they occupy is at issue.
"In the sixties and seventies, the native rights movement was effective at this. There were encampments around potential nuclear-power sites in the eighties. None of the protesters today actually want to take over Wall Street, so in a sense they had to move on," Dr. Reed said.
Occupations, he argues, have a built-in problem: They take a lot of effort to maintain and as time goes on, risk becoming stagnant.
"In many ways the authorities may have done the protesters a favour," Dr. Reed added. "The encampments ran their course. Now the protesters' energy can be used to push for actual changes to legislation."