DETROIT (WWJ) – An investigation is underway in Detroit — after reports that 911 calls residents placed were returned by a busy signal as their apartment building went up in flames yesterday.

Detroit Deputy Fire Commissioner Dave Fornell says — not so fast — they’re working to determine if that happened:

“That we don’t know — we are investigating that right now, but until the investigation is complete I don’t have any information on that at this point,” said Fornell.

The apartment along Woodward near the Highland Park border went ablaze Saturday morning. One person was injured jumping from a the third floor.