A woman who was seriously injured in a Burnaby apartment fire this week has died from her injuries.

Sudeshna Nath, 60, died in hospital late last night. She suffered a heart attack while trying to escape the flames late Monday night. Her 19-year-old son remains in critical condition in hospital.

The teen was badly burned while trying to save his mother and an eight-year-old boy -- who is also in critical but stable condition.

The fire apparently started in the lobby of the three-story complex in the 3500-block of Smith St. around midnight on Monday.

By the time fire crews arrived at the scene some residents were already leaping out windows.

Several suites were seriously damaged before crews managed to contain the fire, which is considered suspicious. Some building residents claim it likely started in piles of junk, including a couch and a Christmas tree, left in the building lobby.

Five other residents suffered minor injuries.

With files from The Canadian Press