A woman is dead after an assault in the city's Weston neighbourhood on Friday night, Toronto police say.

Emergency crews were called to an apartment building in the area of Weston Road and Lawrence Avenue West at around 6:45 p.m. for a female in distress.

Det. Sgt. Rob North told CP24 that the female victim was assaulted on an elevator in one of the upper floors of the building.

When officers arrived, they located the woman with obvious trauma to her upper body, North said.

The victim was taken to a hospital with life-threatening injuries. She was later pronounced dead.

The homicide unit has taken over the investigation.

North said the suspect fled the building on foot and headed west on Weston Road.

The suspect is described as a 25-year-old man, approximately six-foot-two, with a light brown complexion and thin build.

When asked if the victim was sexually assaulted, North said it is too early in the investigation.

"Based on the video I have seen so far, it is an assault," said North, adding it may change in the future depending on the evidence.

North is reminding the public to be vigilant.

"When you are walking around the streets, especially late at night, just be aware of your surroundings."