St. Catharines Fire and Emergency Services is reminding residents to stay focused in the kitchen.

This comes after a fire on Sunday evening caused extensive damage to two apartments and left their occupants displaced — a result of unattended cooking, said a news release from the city Tuesday.

Fire crews were called to a two-family dwelling on Byrne Boulevard just before 10 p.m. after a report of a structure fire.

The fire started in the kitchen of the lower unit and caused heavy smoke with zero visibility.

Firefighters were able to bring the fire under control quickly, but the building sustained extensive damage to the lower unit as well as smoke damage throughout.

Total damage is put at more than $100,000.

A resident of the lower unit needed to be evacuated by fire crews and examined by paramedics, but did not require transportation to the hospital, said the fire department.

The occupants of both units were displaced as a result of the fire and the Red Cross was contacted to assist.

The cause of the fire was determined to be as a result of cooking oil igniting after the occupant left the room briefly.

“Cooking fires remain one of the leading causes of fires in Ontario,” said fire Chief Jeff McCormick.