Canadian officials Tuesday, July 9, 2013, strongly suggested that criminal intent contributed to the 72-car train that derailed July 6 in Lac-Megantic, Quebec, though they declined to provide details.

Quebec police inspector Michel Forget said investigators had found evidence leading them toward a criminal probe. That development runs somewhat counter to numerous scenarios offered earlier for the explosion’s cause, including whether tank cars with other hazardous commodities besides crude oil were included in the consist, or whether natural gas pipes were severed when the tank cars derailed and piled into buildings, igniting and resulting in explosions and fire. Also cited as an igniting force: a cut of propane tank cars on a siding, struck by the runaway train consist when the latter derailed.

Crew and/or railroad negligence also continue to be offered as a possible cause of the incident by some, now including Rail World CEO Edward Burkhardt, also chairman of Herndon, Maine-based Montreal, Maine & Atlantic Railway (MM&A), the short line involved. Burkhardt said Wednesday the engineer involved has been suspended. Others have noted the use of a one-person crew led to human error or oversight, contributing to the incident. Transport Canada approved one-person train operations for the MM&A last year.

Burkhardt had planned to visit Lac-Megantic on Tuesday to get a firsthand look at the significant damage levied on the town, but rescheduled the trip to Wednesday. Upon arrival Wednesday, the CEO allowed that the train’s engineer may not have set enough handbrakes to effectively secure the train. MM&A President and CEO Robert Grindrod did visit Lac-Megantic prior to Wednesday, telling media representatives, “I’m devastated for the damage, I’m devastated for the loss of life and injuries and everything else that’s happened.”

Burkhardt has been criticized sharply—and reportedly threatened via email—for arriving in Lac-Megantic five days after the incident, as well as for earlier statements suggesting firefighters in nearby Nantes, Quebec, shut down a locomotive while putting out a small fire on the locomotive. That, he had suggested, caused the brakes to release and the runaway train to travel toward Lac Megantic. A spokesman for the firefighters vigorously disputed the assertion. Canadian federal officials said Tuesday the train in Nantes should not have moved, even it had lost air pressure to the brakes, prompting suspicion of unauthorized actions.

Lac-Megantic lies roughly 20 miles northwest of the Maine border and about 150 miles east of Montreal. A route map of the MM&A shows the town to be the last major station prior to MM&A’s crossing the Quebec-Maine border.

Authorities Tuesday said at least 15 people had died from the explosion, up from five deaths confirmed on Sunday. On Wednesday the number of people still unaccounted for, and presumed to have perished, was increased from an estimated 35 to 45.