Reports of smoke at the Downtown Crossing station triggered massive disruptions to the MBTA's core subway system on Tuesday, Jan. 16, 2024, shutting down more than a dozen stops on a day when the morning commute was already snarled by winter weather. (Photo provided by State House News Service)

This story has been updated.

FOR AT LEAST an hour Tuesday morning, three of the four MBTA subway lines operating in Boston’s downtown core were out of commission.

An electrical fire near Downtown Crossing Station shut down the Red Line and the Orange Line. The Green Line was shut down for previously scheduled track work, which meant the only subway line running normally was the Blue Line.

Brian Kane, the executive director of the MBTA Advisory Board, which represents T service communities, said he hadn’t seen anything like it since everything was shut down at the MBTA during the snowmageddon of 2015.

The cause of the fire is under investigation, but Kane said he suspects the blaze was caused by water containing salt used on roadways leaking into underground electrical equipment and causing a short-circuit.

James Aloisi, a former state secretary of transportation and a board member of the advocacy group TransitMatters, said the large-scale suspension of service Tuesday morning raised questions about the MBTA’s resiliency to withstand unexpected events. “On a day that’s really lousy for driving, you want people to use transit but you’ve only got one line running,” he said.

MBTA General Manager Philip Eng in a statement released Tuesday evening apologized for the inconvenience and placed the blame on “years of neglect and disinvestment.'”

“While we do not have precise figures, we recognize that each inconvenience to every rider, no matter how brief, represents a delayed connection or a moment of uncertainty,” he said. “The challenges experienced today only strengthen our resolve to address years of neglect and disinvestment and focus on creating sustainable solutions that minimize failures like these going forward and eliminating single points of failure. We hope our riders know their safety was paramount in our response today, as it always is.”

The fire was first discovered at around 8:20 a.m. when smoke began emanating from a manhole cover about 150 feet from Downtown Crossing Station. That prompted the suspension of Red Line service between JFK/UMass and Harvard.

The fire was traced to a cable that supplies electricity to the Orange Line. That discovery prompted the shutdown of the Orange Line between North Station and Back Bay starting at 9:40 a.m. while temporary repairs were made. Service was restored on the Orange Line at 10:40 a.m. and at 10:50 a.m. on the Red Line, but MBTA announcements on Twitter noted service was resuming with 20-minute delays.

MBTA officials said no trains were stranded between stations, so passengers were not stuck underground. About 50 shuttle buses operated along the path of the Red Line closure during the shutdown and shuttle buses operating along the closed Green Line between Kenmore and Copley extended their run to North Station during the shutdown.

On Twitter, many riders complained about the absence of shuttle buses at various T stops, their inability to board the few that arrived, and the lack of information supplied by T staff on the ground.

Bruce Mohl oversees the production of content and edits reports, along with carrying out his own reporting with a particular focus on transportation, energy, and climate issues. He previously worked...