The Transportation Safety Board is investigating after an employee died on the job at a CN Railway yard in Vaughan, York police said Thursday.

Emergency services were called to MacMillan Yard shortly before 2 a.m., Const. Andy Pattenden said.

They found a CN worker trapped beneath a rail car that had derailed and fallen on its side, he said.

The employee died as a result of injuries sustained in the incident, Pattenden said. The age and sex of the deceased was not released.

CN spokesperson Jonathan Abecassis confirmed the death in an email statement.

"We want to offer our sincere condolences to the employee's friends, family, loved ones, and community in these tragic times," he said.

"As the investigation is ongoing, we will not be commenting any further."

Chris Krepsky, spokesperson for the TSB, said that a team of investigators was deployed to the yard.