only on 5, making room for a major development. work is finally starting on yerba buena island as well as treasure island for a project 20 years in the making. but as kpix 5's emily turner tells us, the billion-dollar development comes at the cost of hundreds of trees. emily. >> reporter: veronica, this morning one woman described this scene as something from a scary movie and you can see why she would feel that way. it is actually the scene of san francisco's largest and latest development. it is the beginning of something big. huge actually. but the development of yerba buena island and treasure island means the end of these places as we know them. >> i like it the way it is. >> reporter: but it's changing all in the name of big development. the plan has been in the works for 20 years and this is the first phase of it. hundreds trees are going