The train derailed Sunday morning near the Spuyten Duyvil station. Four people were killed in the accident.
Transit authorities say commuter rail service in Connecticut is expected to resume in full by rush hour Wednesday morning.
Investigators will look closely at a broken section of rail to see if it is connected to the commuter train derailment and collision outside New York City that left dozens injured.
Two commuter trains packed with rush-hour commuters collided in an accident that sent about 70 people to the hospital, severely damaged the tracks and threatened to snarl travel in the congested Northeast Corridor.
Connecticut Gov. Dannel P. Malloy says a total of 60 people have been taken to hospitals with injuries from a collision between two New York-area commuter trains.
The MBTA trolley driver blamed for causing a trolley crash last week at Boylston Street station has been fired.
Three dozen people were hurt when two Green Line trains collided at the Boylston Street station just before noon Thursday.
Following two previous crashes in 2008 and 2009 in which one person died The National Transportation Safety Board made specific recommendations. But because of cost those safety improvements are still not in place.
Firefighters in Waltham say they will practice responding to a train crash on Sunday in a rescue drill that will cause a traffic detour.
Producer Dave Mager compiles the top soundbytes of the week.