With the manhunt playing out in Boston, transit to the city has all but stopped.
Low-cost bus company Megabus has canceled service between Philadelphia and Boston.
Megabus has also canceled at least 18 buses to other cities including New York, New Haven, Conn., Hartford, Conn. and Burlington, Vt.
BoltBus, another low-cost line, has also suspended service into and out of Boston. In a post on their website, Bolt says customers affected by the shutdown will get a refund.
Amtrak has indefinitely suspended all service from New York to Boston. The rail line had previously only stopped trains about an hour south of the city in Providence, R.I.
Amtrak is advising customers to follow their Northeast Corridor Twitter account for service updates.
The Massachusetts Bay Transportation Authority, which operates commuter trains into Boston as well as the city's subway -- called the T -- and the city's buses suspended all operations.
Air service to Boston is still operational, though security is greatly heightened. Planes continue to take off and land at Logan International Airport.
JetBlue, the largest airline in Boston, is allowing anybody scheduled to fly to or from Boston to change their ticket for free.