Influential social activist and author Jane Jacobs, who wrote The Death and Life of Great American Cities, died Tuesday morning in Toronto. She was 89.

According to unconfirmed reports, Jacobs died at Toronto Western Hospital after suffering what appeared to be a stroke. She would have been 90 next week.

Born in the United States in 1916, Jacobs had lived in Toronto since 1968.

Jacobs was one of the most influential critics of urban planning, though she had no professional training in the field.

Jacobs challenged assumptions she believed damaged modern cities: that neighborhoods should be isolated from each other; that an empty thoroughfare is safer than one teeming with life; that the car represents progress; and that long straight streets were better than short winding ones.

Jacobs frequently wrote about the dangers of urban sprawl, and was a leader in the fight to preserve neighbourhoods and kill expressways.

In the early 1960s, she led the successful opposition in New York City's Greenwich Village against a proposed expressway through Washington Square.

In Toronto, it was her leadership that spurred the movement to halt the proposed Spadina Expressway, which would have cut a strip through the city.

At the time, she wrote a newspaper article criticizing city planners for their vision to 'Los Angelize' what she described as "the most hopeful and healthy city in North America, still unmangled, still with options."

"Jane Jacobs will be remembered as one of the great urban thinkers of our time," Toronto Mayor David Miller said Tuesday in a statement.

"Her contributions and insights have forever changed the way North American cities are developed."

She is perhaps best known for her first book, The Death and Life of Great American Cities, a critique of the urban renewal policies of the 1950s that established her as a force to be reckoned with by city planners and economists.

Jacobs, born May 4, 1916, grew up in the coal mining town of Scranton, Pennsylvania.

When she graduated from high school, she trained as a stenographer, but took an unpaid position as the assistant to the women's page editor at the local newspaper.

During the Depression years, she moved to New York City, where she held a variety of jobs, working mainly as a stenographer and freelance writer.

At age 22, she enrolled at Columbia University, but she returned to writing after two years.

In 1944, she married architect Robert Jacobs.

Jacobs lived for many years in Manhattan before she and her husband left for Canada in the late 1960s, unhappy that their taxes were supporting the Vietnam War.

Though the move was supposed to be temporary, it became permanent.

Her marriage to her husband was a happy one that lasted more than 50 years, before he died in 1996 of lung cancer at Toronto's Princess Margaret Hospital, a hospital he had designed.

Former Toronto mayor John Sewell told The Canadian Press he had lunch with Jacobs frequently over the past four or five years.

"She was very straightforward, very curious about the world. She was always saying `what's going on?', 'so what's the news?' 'what have you been doing?' Just so curious about how things worked. That to me was just a very endearing trait," he said Tuesday.

Looking back on her life, Jacobs herself is quoted as saying: "Really, I've had a very easy life.

"By easy I don't mean just lying around, but I haven't been put upon, really. And it's been luck mostly. Being brought up in a time when women weren't put down, that's luck. Being in a family where I wasn't put down, that's luck. Finding the right man to marry, that's the best luck! Having nice children, healthy children, that's luck.

"All these lucky things."

Jacob's literary credits also include: The Economy of Cities; The Question of Separatism, Cities and the Wealth of Nations; The Girl on the Hat, Systems of Survival; A Schoolteacher in Old Alaska; and The Nature of Economies.