NIAGARA FALLS, N.Y. (WBEN/AP) — Lois Gibbs, the woman who led efforts to investigate the industrial contamination of Love Canal is back in her former hometown for the 35th anniversary of the environmental disaster.

In 1978, the government officially told residents in the Niagara Falls neighborhood known as Love Canal learned that they were living in a toxic zone because their homes had been built on an industrial waste site blamed for health problems suffered by many families.

"The people who are responsible for this; Occidental Petroleum, the city of Niagara Falls, the state of New York, and the federal environmental protection agency, not only should be ashamed of what they did, but they put in jail" said Gibbs.

Lois Gibbs joined other activists Tuesday for a walking tour of her old neighborhood to commemorate the evacuation's anniversary and to bring attention to other problems in the area.

Hundreds of Love Canal residents had to move out of their homes in one of the nation's worst environmental disasters.