I heard that the high school where Grease was filmed(in California) was torn down. It that true and when?

It was filmed at a real highschool in California in the 1970's.

Some of the movie was filed at Venice High, I was there while they were filming some of the scenes.

No it is still there but Venice High isn't the name

No. The school is still there. it just a little different from the outside were the bushes were there and now they're gone.