Fire investigators determined the cause of the fire that ripped through the Drostes Jewelry Store on Evansvilles east side. It happened August 24th. Drostes had been doing some work on their roof. Investigators say some wood shingles and tar paper had been removed and were on the ground, covering up some landscape lighting. When those lights automatically came on, the heat ignited the shingles and paper. The Evansville Fire Department said insurance investigators confirmed their cause.