MOSCOW (AP) — A fire in a retirement home in Moscow killed four people and injured 16 others but firefighters managed to rescue 50 people from the burning building, emergency officials said Thursday.

The fire broke out Wednesday night in the basement of the building and quickly spread to the ground floor. It was most likely caused by a malfunctioning electric cable, authorities said.

The retirement home in northwest Moscow housed elderly people with limited mobility according to Russian media reports.

Fifteen men and women aged 66-90 remained hospitalized on Thursday with injuries from burns and smoke inhalation, the Interfax news agency reported. All were in grave condition and four were put on ventilators, it said. One person was apparently discharged.

Police have launched a criminal probe into the fire.