Commuter rail signal worker placed on administrative leave after fatal crash in Wilmington

A MBTA commuter rail logo.Craig F. Walker/Globe Staff

The signal maintainer who officials said failed to restore a railroad crossing safety system less than an hour before a fatal train crash in Wilmington has been placed on administrative leave, the MBTA’s contractor Keolis said Monday.

Investigators are focusing on “human error” as the cause of Friday’s crash, in which an inbound commuter train struck a car in the crossing near the North Wilmington MBTA Station shortly before 6 p.m., Massachusetts Bay Transit Authority general manager Steve Poftak said over the weekend. The driver of the car, Roberta Sausville, 68, was killed just blocks from her home. No one on the train was injured.

MBTA officials said the crossing gates and flashing lights meant to keep cars off the tracks did not activate in time because the worker likely did not return the system to its normal operating mode after conducting regularly scheduled maintenance on the safety system.

The employee worked for Keolis, the company that runs the MBTA’s commuter rail system. The company would not say whether the leave is paid or unpaid.

Crossing protections are normally triggered by an oncoming train and are often disabled during maintenance and testing, said Robert Halstead, a New York-based railroad accident reconstruction expert with Ironwood Technologies. It’s possible that the person doing the maintenance left the system or parts of the system disabled, he said.

“That is the first thing I look for,” Halstead said. Another possibility is rust buildup on the rail that prevents the gates and flashers from detecting an oncoming train, Halstead said. When this happens, the gates usually engage later than they should, Halstead said.

MBTA spokesman Joe Pesaturo said Monday that investigators had staged a full reenactment of the event and had eliminated the possibility of rust buildup.

“Keolis and MBTA personnel were on scene over the weekend, performing multiple tests at the crossing,” Pesaturo said by e-mail. “In each instance, the safety system performed in the manner in which it was designed. Investigators found no defects nor any other problems with the various elements that comprise the infrastructure of the railroad crossing’s safety system.”

Pesaturo said the commuter rail train had not stopped at the nearby North Wilmington station before the crash. At the time of the crash, the train was heading to its next stop in Reading on its way to Boston’s North Station, according to its schedule.

At the time of the crash, the train was traveling 47 miles per hour in a 60-mile-per-hour zone, Pesaturo said. As the train approached the crossing at Middlesex Avenue, the engineer sounded the horn and engaged the emergency braking system, Pesaturo said.

MBTA officials declined to say whether there are safeguards in place in case the crossing alert system is shut down. But railway safety specialists said systems are designed to limit the impact of human error as much as possible. For instance, the person performing the maintenance is usually required to get verbal permission from the train dispatcher or the signal supervisor, including confirmation that the gates are working again, before leaving.

“If they locked out and forgot to reengage the system, that’s a fault of the system,” said James Sobek, a senior accident analyst at Wolf Technical Services. “When you say, ‘We are done at the crossing, you can return it to full service’, the question would be, ‘Have you activated and demonstrated that the system is working?’”

Wilmington town manager Jeffrey Hull said the fatal crash raises questions about the systemic controls in place to alert drivers to an oncoming train.

“It does raise concerns about how reliable the systems are,” he said. “For a lot of us here in town, it is concerning that something you presume is working the way it should, in this particular instance didn’t. We have multiple rail crossings in town, it becomes second nature to cross a rail crossing.”

The Middlesex District Attorney’s office, which is investigating the crash, declined to comment.

Boston Mayor Michelle Wu said she will continue to work with the MBTA on ensuring that safety is “a baseline for everyone who interacts with our system.”

At a news conference, Governor Charlie Baker said the crash was “a horrible tragedy.”

“It’s currently under investigation by the MBTA and as soon as they complete that investigation, they’ll make that information available to the public,” he said.

The Middlesex Avenue crossing is designated as a “quiet zone” by the Federal Railroad Administration, Pesaturo said. In quiet zones, train engineers are not required to sound their horns as trains approach crossings, as they are in areas without the designation. The horns can still be used in emergencies, according to the FRA.

To win approval for a designated quiet zone, municipalities must install extra safety measures at crossings meant to block drivers and pedestrians from going around the gates, such as medians on one or both sides of the tracks or a gate system that blocks all lanes of traffic.

The MBTA does not support quiet zones. In a 2019 letter to the Needham town manager, Poftak wrote that quiet zones compromise the safety of MBTA employees, customers, and the general public. There are 29 quiet zones in Massachusetts, according to the FRA.