State regulators say they have started a formal investigation into the San Francisco Municipal Transportation Agency. Inspectors apparently found track defects and other problems at the agency.
The California Public Utilities Commission says the defects and problems have to do with the train control system that runs Muni's trains.
The CPUC reportedly found violations in more than 20 inspections between July 2009 and January of this year.
Muni's chief of transit operations told the San Francisco Chronicle the agency is working closely with the CPUC to remedy the issues.