A man is in hospital in critical condition following a fire inside an empty semi-trailer on Logan Avenue this afternoon.

Emergency crews were called to a side yard in the 300 block of Logan, near Lizzie Street, shortly before 2 p.m.

Marilyn Sinclair, who lives nearby, said she saw firefighters moving through thick black smoke to get to the trailer.

"Slowly they opened it and there was just black smoke coming out," she said.

"After that, we saw them carrying someone on their shoulders and they have been trying to do life support there, I guess."

The fire happened inside a detached white truck trailer on the lot, said fire platoon Chief Ted Kuryluk.

"It was basically plastic and insulation burning on the inside. It was an empty trailer," he said.

A green shipping container next to the trailer was not damaged.

Kuryluk said a middle-aged man was found inside the trailer. Emergency personnel tried to resuscitate the man at the scene before he was taken to hospital in unstable condition, he added.

Police told CBC News the person was listed in critical condition.

The cause of the fire is under investigation.