A Boston/Cambridge shuttle had to stop its route after smoke was seen coming out of the back on Sept. 7, according to student accounts and Director of Public Safety Ed Callahan in an email to the Justice. No passengers were injured and another bus arrived within 30 minutes to pick up the students from the location of the incident.

"[W]e had smelt smoke on the bus. We suddenly stopped and had to evacuate the bus," wrote Flora Wang '14, one of the passengers, in an email to the Justice. "There was [a] large amount of smoke billowing out of the back of the bus."

"There was a strong smell, an alarm, and lights on the dashboard," recalled Mia Katan '15, another passenger, in an email to the Justice. "The bus driver pulled over and told us to get out because the bus was on fire."

The incident took place off campus while the bus was on the normal route. Callahan wrote he believed it took place "close to Brandeis."

According to Callahan, an alternator malfunctioned, causing the bus to smoke, "which necessitated the bus be stopped for [the] safety of passengers." All passengers were moved to a second bus.

This is not the first time a shuttle has experienced malfunctions. In March 2012, a Crystal Shuttle bus caught fire while on Loop Road. The Waltham Fire Department and University Police were called to the scene to put out the fire. No injuries were reported. The cause of the fire was unknown.

Last week's incident comes shortly after the switch to a new transportation provider, Joseph's Transportation, which replaced Crystal Transport this semester.

According to Callahan in a Sept. 3 Justice article, the change to Joseph's Transportation was made after the contract with Crystal Transport "went out for bid."

While the details of the contract are not known, Callahan said that he believed the switch to Joseph's Transportation would allow the University to save money.

Katan later wrote in her email that the event was "fairly calm." "I never saw any flames and no one was hurt," she wrote.

-Sara Dejene, Phil Gallagher contributed reporting.