Water bombers were used in the efforts to put out the fire near Prince George Saturday. ((David Mah/Canadian Press))

The train collision and subsequent fire in Prince George last weekend was caused by human error, says CN Rail.

On Saturday two CN trains carrying fuel and lumber collided, setting their cargo ablaze along the Fraser River.

CN spokeswoman Kelli Svendsen said that an "experienced manager" had allowed the slow-moving northbound and southbound trains to collide, sparking the huge fuel and lumber fire.

Svendsen said the manager would be disciplined for the latest incident.

"There are procedures that employees have to follow when operating trains. When those procedures are not followed there are consequences, and the consequences are the same for all employees, management or union," said Svendsen

This latest accident happened one day after the rail company was slapped with five charges over the 2005 Cheakamus Canyon derailment that killed half a million fish.

Ben Van Nostrand with B.C.'s Ministry of Environment said the environmental damage in Prince George could have been much worse, since little spilled fuel made it into the riverafter it caught fire and burned offin a huge plume of black smoke.

"Had that not caught on fire we would have had the diesel flowing directly into the Fraser River," said Van Nostrand, "We do have, of course, the air quality impacts, because of the fire."

Health officials issued a voluntary evacuation order for people living nearby on Saturday. No one was hurt in the collision.

Despite the most recent crash, and the charges laid on Friday for the Cheakamus Canyon derailment, CN maintains it has a good safety record. The company says it cut year-to-date main track accidents from 79 in 2005 to 63 this year.

The Transportation Safety Board is still investigating the cause of the latest accident.