Canadian National Railway Co said that it appeared that three newer crude railway cars involved in a derailment and fire in Plaster Rock, New Brunswick last week fared better than two older tank cars.

A total of 19 cars and one locomotive on a 122-car, four-locomotive train went off the rails in the rural area last Tuesday, sparking a fire that burned for several days. Almost half the derailed cars carried crude or liquefied petroleum gas (LPG).

“A senior CN safety officer told the Ottawa safety forum yesterday that the new specification DOT-111 tank cars involved in the accident appeared to fare better than the older DOT-111 tank cars,” CN spokesman Mark Hallman told Reuters, referring to an event hosted by the Canadian Transportation Research Forum.

Montreal-based CN did not provide any further detail on the degree of damage and did not specify the ways in which the newer cars fared better.

The railway repeated that it is still investigating damages to all of the tank cars in the New Brunswick accident and the volume of material affected. It is working with the Transportation Safety Board of Canada’s probe.

Older DOT-111 model tankers do not comply with stricter voluntary standards adopted in October 2011 and regulators have deemed the older cars vulnerable to leaks and explosions.

The New Brunswick accident happened one week after the fiery crash of a crude oil train in North Dakota. They were the latest in a series of derailments involving dangerous goods in the past year.

Canadian and U.S. regulators have come under intense pressure to toughen industry rules, particularly after a runaway train disaster in Quebec killed 47 people last summer. A rise in shale oil production has spurred a huge boom across the continent in shipping crude via rail, as pipeline capacity remains constrained. (Reuters)