a shuttle service on February 27, 1928. The shuttle service was replaced by buses on August 6, 1939, but streetcar service returned on the full length of the line on December 17, 1944. On June 6, 1948, the Transbay Terminal became the inner terminus of the line. While many streetcar lines were permanently converted to buses after World War II, the M Ocean View remained a streetcar line due to its use of the Twin Peaks Tunnel. Service was diverted to Duboce Avenue, Church Street, and 17th Street on December 2, 1972, due to construction of the Market Street subway. On August 30, 1980, the line was extended to Balboa Park BART station. The full line was partially converted to modern light-rail operation with the opening of the Muni Metro system on December 17, 1980. Eureka Valley in the Twin Peaks Tunnel was originally a stop in regular service, but the station was closed in 1972 and replaced, ten years later, by Castro Street Station when the Market Street subway system opened. In the early 1970s, Muni began planning an extension of the J Church line over new track to Balboa Park station, then over the M Ocean View line to the high-ridership San Francisco State University station and Stonestown Galleria station. A Final Environmental Impact Statement for the new track was released in 1983; it was opened for non-revenue moves in August 1991 and began revenue service in June 1993. Original plans called for the two existing stations to be rebuilt with high-level platforms, and a pocket track to allow J Church trains to turn back. After objections from neighbors, the pocket track was removed from the plan. The first phase of the 19th Ave. Platform & Trackway Improvement Project required the line to replaced by buses south of St. Francis Circle from June 19 to October 23, 1993; the new platforms at the two stations were opened when service was restored, though several minor stops along 19th Avenue were left permanently closed. The second phase required full bustitution beginning on July 30, 1994; rail service was restored to Stonestown on November 19 for holiday shopping, and on the rest of the line on January 28, 1995. Some weekday J and M service was through-routed beginning on March 27, 1995; this lasted until a rail replacement project on the M in February 1998. Full combined J/M service was planned