An all-day disruption involving San Francisco's Muni subway system Friday was caused by a failure of an overhead wire splice, according to the San Francisco Municipal Transportation Agency.
Around 6:30 a.m., a train traveling to the Civic Center Station tore down more than 1,000 feet of wire and supporting hardware, according to SFMTA officials.
The wire became tangled in the top of a two-car train, damaging components on the top of the train and shattering train windows.
The wire splice is responsible for transmitting electricity to power the train.
There were few passengers onboard the train, and they were able to safely exit at the Civic Center platform.
The incident caused extensive overhead infrastructure damage, and crews had to first cut free the old wire and tow the train from the scene, officials said.
Then, crews brought in a specialized repair vehicle to install new electrical wire.
The incident caused significant Muni delays into Friday evening when service was fully restored.