Human error is being blamed for a freight train derailment in the heart of Toronto Sunday morning that had crews scrambling to contain a diesel fuel leak.

The derailment happened after a train struck the tail of another train at about 5:20 a.m. near Dupont and Bathurst Sts., Canadian Pacific Railway spokesperson Martin Cej told the Star.

No one was injured in the collision and subsequent derailment and the diesel fuel leak, which Toronto police said had not been a threat to public safety, was quickly contained.

Cej said that one car was carrying batteries and aerosols, which are classified as “dangerous goods” under Canadian regulation, but they did not leak, he confirmed.

City councillor Josh Matlow raised new concerns Sunday about freight trains running through densely populated neighbourhoods.

“While it was incredibly fortunate no one was hurt today, this derailment should act as a wake-up call for the federal government to move swiftly on rail safety,” he said.

This spring, Mayor John Tory, Matlow and 16 other councillors whose wards are nestled by rail lines, signed a letter sent to Marc Garneau, the federal Transport Minister, calling for better rail safety.

The 2016 federal budget allocated $143 million to be used over three years to improve rail safety.

Cej said “early indications” point to human error as the cause of Sunday’s collision and derailment and that equipment failure was not a factor.

Bartlett Ave., north of Dupont, was closed while police and rail officials investigated the incident.

Although there were no dangerous goods on board either train Sunday, roughly 9 per cent of goods transported by CP in Ontario are regulated dangerous goods, according to a disclosure to Transport Canada for 2015.

A 2014 investigation by Star reporter Jessica McDiarmid monitored CP’s rail line that crosses Barlett Ave. on its way to Dupont St. in the Junction before it goes northward, west of the Don Valley.

Between two 12-hour shifts, 7 a.m. to 7 p.m. and 7 p.m. to 7 a.m., the Star found that more than 130 cars and tanks carried dangerous goods such as crude oil, methyl bromide and ethyl trichlorosilane, and more.

A little over three years ago, a train hauling 72 cars of crude oil, derailed in Lac-Mégantic, Que. It resulted in an inferno that killed 47 people, and spilled six million litres of crude.

Since the 2013 Lac-Mégantic disaster, rail companies are required to provide information to municipalities for emergency planning, however, under strict confidentiality agreements. Canada’s largest railroads already did this upon request.

In February 2015, the federal government introduced a bill that increased the amount of insurance railways must carry to cover costs in the event of a derailment.

With files from Fakiha Baig and Star Staff