Desert Line, at the time owned by Southern Pacific (SP) railroad. The SD&AE offered freight service between San Diego and points east with a line that traveled between Downtown San Diego, San Ysidro, Northern Mexico, and Imperial County before connecting with the rest of the SP system in Plaster City, California. The hurricane caused $1.3 million worth of damage to the line ($ adjusted for inflation), primarily in Imperial County, east of San Diego. Freight service was suspended, and in light of the extensive damages, SP petitioned the Interstate Commerce Commission to abandon the SD&AE on August 9, 1977. The MTDB immediately began studying the SD&AE corridor between Downtown San Diego and the San Ysidro Port of Entry for joint use by electric light rail and freight trains. In June 1978, the MTDB found the entire joint-use project feasible. At the same time, the San Diego County Board of Supervisors became concerned about the potential loss of freight service on the SD&AE, which was seen as vital to the county's economic interests and the continued viability of San Diego as a deep-water port. The county commissioned its own study to examine using a portion of the SD&AE tracks for passenger service which would share the track with freight services, the motivation being the transit services could share the costs of maintaining the tracks. San Diego County proposed operating either commuter rail trains or self-powered diesel rail cars. Implementation In 1978, the Interstate Commerce Commission denied the request to abandon the SD&AE, prompting Southern Pacific to offer the railroad for sale to anyone willing to maintain freight operations on the line. The MTDB stepped in and offered to buy the SD&AE for $18.1 million if the Southern Pacific fully repaired the hurricane-damaged line. The deal closed on August 20, 1979, with the final acquisition occurring on November 1, 1979. The MTDB quickly secured a deal with the San Diego and Imperial Valley Railroad to continue freight service along the line. The purchase gave MTDB ownership of two sections of right-of-way that could be used for mass transit: the SD&AE Main Line from Downtown San Diego to San Ysidro, and the SD&AE La Mesa Branch from Downtown San Diego to El Cajon. With all the planning in place, construction of the "South Line" transit corridor (the southern portion of today's Blue Line) was able to begin just one month after acquisition in