BART riders may face an uncertain commute for the next few months. An electrical surge has crippled 58 cars in the fleet and service was entirely shutdown between the North Concord and Bay Point stations on Friday. BART is working to fix the problem, but the agency also made an unusually frank announcement on Twitter, stating that much of its system is at “the end of its useful life.” Forum discusses BART’s short-term reality and long-term fate.