As the bulldozer pulled up in front of Harlem's Public School 76, some of the children noticed the rumble.
"Mr. Goodridge, there's a bulldozer in the garden," one of the seven-year-olds told his teacher.
When Tom Goodridge looked outside, he saw the bulldozer had crashed through the wood-framed wire fence, laying waste to the plant beds and trees he and his students had cultivated over the years. He dashed out the door.
"Stop! What are you doing?" he asked the hard-hatted foreman.
"This is city land!" the man retorted as he turned his back and resumed demolition.
This scene from last November sent shivers through community gardeners in New York and other cities across the nation. For decades, many urban communities have cleaned up abandoned, garbage-filled lots and planted gardens - often with their cities' encouragement - in an effort to improve their neighborhoods. As the economy thrives, however, these city-owned lots are now prime targets for development.
"Everyone is terrified by the New York situation," says Sally McCabe of the American Community Gardening Association in Philadelphia. "It's waking us up - making us realize we need to court our governments, make them realize what we're doing and why it's so important for our communities."
So far, such tactics haven't worked in New York. "This is a free-market economy," said Mayor Rudolph Giuliani, responding to protests in January. "Welcome to the era after communism."
So far, 44 gardens have been bulldozed, according to the New York City Gardening Association, a private, non-profit group. The city plans to auction 112 more in May, as part of an effort to sell some of its 11,000 vacant lots. It contends the land is needed to build affordable housing.
But many community activists find it ironic that the work neighbors did to improve their communities and increase the value of the land is one reason the gardens are threatened. The Harlem school's garden - named the Garden of Love by the students and built in 1990 with help from the local Ethiopian Coptic Church - was one of approximately 700 gardens on city-owned lots.
Like others, it received funds from the city's "Green Thumb" program, which provides permits, water, and fencing for communities to clear neighborhood eyesores.
"It was just a dangerous, nasty spot full of construction debris and old refrigerators, tires - a crack house was behind it," says Goodridge. "We made it into a haven, a place of flowers and trees."
Community gardens began blooming in big cities in the 1960s and '70s as a result of the civil rights movement and its effort to find ways to improve decaying urban areas.
"This became a form of empowerment for many African-American neighborhoods, and they continue to be a source of community, grass-roots activism," says Sam Warner, author of "To Dwell Is to Garden," a history of community gardens in the US.
MS. McCabe says that the gardens help create communities in the inner city. "When people are involved in a community garden, they come out of their doors, they begin to know each other and talk to each other and take care of each other."
The city contends gardeners knew from the start use of the land was temporary. "It's leased to them with the understanding that they could be sold," says Curt Ritter, spokesman for the mayor.
Mr. Ritter also says the land is now needed to build new affordable housing. "With the return of 300,000 jobs to the city, there's just a growing need for housing," Ritter says.
But activists like David Crane say there are plenty of other parcels the city could use. "Why are they targeting the gardens when there are so many abandoned apartment buildings?" asks Mr. Crane, a member of New York's Lower East Side Collective.
On the block surrounding the lot where the Garden of Love used to be, 11 tenement buildings stand empty, their arched windows and ornate doorways boarded up.
"It doesn't make a bit of sense to me," says Mr. Warner, a visiting professor of urban planning at the Massachusetts Institute of Technology in Cambridge. "These gardens ... probably contribute more to property values than they take away by not producing taxes."
McCabe says community gardens around the country need to find ways to keep the land on a more permanent basis. She suggests trying to change zoning laws to get park status for the gardens, or working with land trusts to purchase the properties.
"Right now we're on tenuous ground," she says.
At the space where Goodridge and his students used to plant trees and listen to stories, a new, shiny chain-link fence now encloses the empty lot. Bricks jut out of the rocky soil still marked by bulldozer tracks, and garbage is already beginning to gather. "The fence says they won't be building anything here soon," Goodridge says.