'A failure in the system': How 2 trains derailed in midtown Toronto

Two trains are travelling in opposite directions, one headed eastbound at 48 kilometres per hour and another westbound at 80 kilometres per hour, before sideswiping each other at a railway crossover in midtown Toronto.

Why did the westbound train operator see the stop signal so late? No, this isn't a high school math problem. It's a key point in the investigation into a Canadian Pacific train derailment that spilled 1,100 litres of diesel fuel near the residential Annex neighbourhood early Sunday morning.

New details emerged Monday as officials looked into the crash that left four rail cars leaning and damaged the tracks.

Neither train was speeding, the Transportation Safety Board says, and CP Rail ruled out mechanical problems, instead pointing the finger at human error, something it reiterated on Monday.

"After careful review, we determined that all track, equipment and signal systems worked as designed, and our preliminary investigation indicates human error is to blame," the railway said in a statement, adding, "We know one incident is too many."

On Monday, the union representing CP Rail workers called that conclusion "premature" but said it understands two of its workers are being investigated.

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The TSB has confirmed that the westbound train, CP 235, came upon a signal displaying a stop indication and its crews made an emergency brake about 300 metres from the crossover, noticing the the tail end of train CP 118 on the track ahead.

"That's unusual, and that's going to be one of the primary focuses of the investigation going forward," acting director of the TSB's rail pipeline investigations branch, Rob Johnston, told CBC News on Monday.

The brakes slowed the train to about 45 km an hour. But it was too late.

'Failure in the system'

Train 235 side-collided with train 118, derailing the last four of that train's cars and its own two locomotives, rupturing the fuel tank of the westbound train's lead locomotive and resulting in a loss of what the TSB believes to be 1,100 litres of its approximately 4,000 litres of diesel fuel.

"It's possible it could be more," Johnston said. "We're going to make an accurate determination of that as part of the investigation."

Train 235's conductor also sustained minor injuries, he said, contrary to reports on Sunday that no one was hurt in the collision.

Under investigation now: The condition of the track infrastructure, crew training, potential crew fatigue, issues with following signal indications and potential crew distraction. But Johnston says one of the most critical questions is what role the absence of a fail-safe physical defence to prevent train collisions may have played in the crash.

"Really what we have here is a failure in the system itself. What gaps existed in the system that allowed this type of accident to happen?" Johnston said, pointing to past derailments including one in Burlington, Ont., in 2012 that left three Via Rail employees dead.

• Via derailment report says crew misperceived warning signal
• 3 Via employees die in Ontario derailment

"In that investigation, the board recommended that Transport Canada require major Canadian passenger and freight railways [to] implement physical fail-safe train controls beginning with Canada's high-speed rail corridors," he said.

'The list keeps growing'

"To date, that hasn't occurred," he said. "And the list keeps growing."

In the U.S., measures are already in place that would bring trains to a stop if a crew does not respond to a signal displayed.

Several railways, including Amtrak, and some local commuter services already employ a variation of what's called Positive Train Control (PTC).

In a statement Monday, Transport Canada said most urban rail transit systems in Canada have some form of automated train control, including the ability to track train movement and location, but so far no major Canadian railroad has implemented the kind of PTC that would give it the ability to stop a train.

The agency said it is closely monitoring the U.S. experience with PTC and working with industry to understand how it might better use the technology here.

Transport Minister Marc Garneau said Monday he intends to act swiftly if it's determined safety lapses caused the derailment.

"My aim is to reduce as much as possible these kinds of incidents, and so I intend to act swiftly if we find that there are things that we need to be doing that we haven't been doing in the past," he said on his way into a cabinet retreat in Sudbury, Ont.

CP said it supports the minister's statement and confirmed it has reached out to the Transport Department. The railway said it is in favour of "meaningful changes that improve rail safety."