BOSTON (AP) – The early morning blaze that killed two Boston University students and seriously injured a third person was caused by a burning candle, fire investigators said Sunday.

Rhiannon McCuish of Mashpee and Stephen Adelipour of Great Neck, N.Y. – both 21 – were killed when fire ripped through the top-floor apartment on Aberdeen Street near the BU campus at 5:15 a.m. Saturday, officials said.

A burning candle – the three-story building was without power at the time of the fire – in the right rear bedroom was the source, Boston Fire spokesman Steve MacDonald said.

“It came in contact with combustible material,” he said, adding that the material it spread to is unknown. “The room was heavily involved with fire. It was totally burned.”

MacDonald would not comment on whose bedroom it was. McCuish and Adelipour were found in separate rooms, he said.

A third victim, whose name was not released, was being treated at Massachusetts General Hospital. The extent of his injuries was unknown.

About 30 people were displaced by the fire. The building had been without power for several hours as NStar crews performed utility work nearby, MacDonald said.

McCuish graduated from Mashpee High School, where she excelled in soccer and track. Mashpee High soccer coach Patricia Morano told the Cape Cod Times that McCuish was humble and gracious, and often said how much she loved her parents and two sisters.

“To have that much skill and to be that humble. I can’t even think of the words to say,” Morano said.

told the newspaper. “She was just a special, special, special kid.”