An intense blaze at a North York highrise early Tuesday morning killed one woman despite her son's desperate attempts to save her.

A 21-year-old man pulled his 47-year-old mother out of their burning apartment but it was too late to save her life.

The man was brought to hospital after suffering from burns to his arms and face. He's also being treated for smoke inhalation.

The fire broke out at around 4 a.m. at the top of an apartment building on San Romano Way in the Jane Street and Finch Avenue area.

The Fire Marshal's office is investigating the cause of the fire and is also looking into whether smoke detectors inside the apartment were working at the time.

"The damage inside that apartment was very intense," a fire official at the scene told CTV Toronto. "It's going to be a while before we can determine where the fire started within the apartment itself."

Neighbours tried their best to help the situation by trying to put out the fire with an emergency fire hose in the hallway while waiting for firecrews to arrive.

"I heard a lady scream out, 'help me, help me,'" said one neighbour, adding she then heard someone break the glass encasement where the fire extinguisher is kept. "The fire alarm was pulled and I called the police at the same time and they told me it was a fire and to get out."