What is the fine-grained topic of the following text: The 16th Street BART station was once a bleak, uninviting, and unsafe transportation hub of San Francisco's Mission District, but a 7-year planning process, community and public agency support, and TE funds transformed the station into the vibrant public plaza and community meeting place it is today. Only return the topic.
Transformation of the 16th Street BART Station in San Francisco's Mission District