A company contracted to provide BART passengers with wireless Internet is suing the transit agency for breach of contract, claiming BART cost them $7 million when it pulled out of a 20-year deal in 2014. In the lawsuit filed Friday in Alameda County Superior Court, attorneys for WiFi Rail Inc. argue the Oakland-based company spent millions of dollars developing infrastructure to deliver WiFi on BART trains and in stations but the cables and other equipment was disrupted by BART employees.