A FIRE ON the Orange Line prompted the MBTA to temporarily shut down service north of downtown on Friday afternoon and forced some passengers to walk along train tracks to safety.

MBTA spokesman Joe Pesaturo said a “small fire” was reported on the tracks between Wellington Station, in Medford, and Malden Center around 3:10 p.m.

The T shut down the electrified third rail and two trains stranded on the track between the two stations were evacuated of passengers, said Pesaturo. He said reports indicated one person fell while disembarking a train and suffered minor injuries. A total of 35 passengers were on both trains, he said.

Passengers on a southbound train walked towards Malden Center to a location where they were able to get off the tracks, and passengers on a northbound train walked back toward Wellington, according to Pesaturo.

While Orange Line trains continued to run south of that area, the T suspended service north of Community College, in Charlestown, dispatching shuttle-buses for transit riders hoping to take the subway.

A Twitter user posted a short video of people exiting a train from the end of an Orange Line car – not the doors along the side that customers use to get on and off the train when it is at a station. Passengers in the video were on the tracks with the third rail right next to them. Another Twitter user showed what appeared to be smoke emanating from right around one of the trains.

The Orange Line mishap occurred in the midst of profound dissatisfaction with the MBTA – spurred, presumably by the enduring problems with the Red Line following a June 11 derailment and the fare hikes that went into effect July 1. The commuter rail system also endured lengthy delays this week after trains hit and killed two people on the tracks.

While its occurrence on a late August Friday might mitigate some of the harm, the suspension of subway service could cause downstream effects to Friday afternoon travelers.

When Transportation Secretary Stephanie Pollack reported on the region’s congestion problems earlier this month, she said Boston roadways are so overwhelmed with vehicles that “relatively small insults – a crash, a work zone that doesn’t get picked up early enough in the morning, bad weather, an event that draws extra people to downtown Boston – all of these can create cascading congestion.”