Haverhill Line update

Got this update from Keolis:

Update on Haverhill Line Derailment and Impact on MBTA Commuter Rail
Tuesday, January 5, 2016
Q: What happened?
A: Around 3:30 a.m. this morning, before passenger service began, a train set heading from Boston to Haverhill derailed between Andover and Lawrence because of a track failure. The cause of the failure is under investigation. The train was not carrying passengers, and the engineer and conductor on board were not injured.

Q: What was the impact on the Commuter Rail system?
A: The derailment blocked trains in both directions between Andover and Lawrence causing significant delays and several cancellations. Haverhill Line passengers were bused between the Andover and Lawrence stations as teams worked to clear the area and repair the tracks. Of the 75 trips operated on a typical morning, a total of 10 trains were cancelled and residual delays impacted the northern lines throughout the morning peak service and into midday hours.

Q: If the incident took place on the Haverhill Line, why were other lines impacted?
A: During peak hours, it takes 25 train sets (locomotive and passenger cars) to operate the five commuter rail lines that serve North Station. In addition to the derailed trainset, four trainsets that are stored at night at the Bradford layover facility were also trapped by the incident and unable to provide their normal service to the north side network, reducing the total fleet by 20%. Train equipment operates across multiple lines, so a train set that starts off on one line will eventually provide service on other lines as well. Thus a delay on one line can have a cascading effect across the system.
To the extent possible, we try to minimize delays and passenger inconvenience by re-assigning train sets and cancelling train trips that will impact the fewest number of passengers. For example, when Train 352 (6:55 from Anderson/Woburn) is cancelled, waiting passengers are picked up 18 minutes later by Train 306 (6:51 from Lowell).

Q: When will the system be operating normally? How will this affect my evening commute?
A: Our Engineering teams were on site beginning early this morning to fix the track. Once repairs were completed, the track was inspected for safety and approved for a return to service by mid-afternoon. The Haverhill Line has been restored to full service and we expect a normal evening commute. As always, we urge passengers to check mbta.com, sign up for T-Alerts, monitor social media or seek assistance from customer service teams in stations. Passengers can also speak to commuter rail customer service agents by calling (617) 222-3200 for the latest information on train service and schedules.