Fire officials said that the massive three-alarm fire at a Crystal Lake apartment building early Wednesday morning was caused by an unattended candle and damage is estimated at $3.5 million.

The Crystal Lake Fire Rescue Department responded at 3:02 a.m. Wednesday to a report of a structure fire in the 500 block of Devonshire Lane.

Six minutes later the first fire crew arrived and found a two-story multi-family apartment style building with flames coming from the roof, Crystal Lake Fire Rescue Chief Paul DeRaedt said.