FITCHBURG (CBS) – Investigators say the explosion that leveled an auto parts store and damaged several homes Tuesday evening was caused by a natural gas leak.

They combed through the rubble on Lunenberg Street Wednesday morning and took away a chunk of a gas pipe.

WBZ NewsRadio 1030′s Karen Twomey reports

John Tate owns Victory Auto which took the brunt of the blast.

He told WBZ NewsRadio 1030′s Karen Twomey that he was inside the building with a customer when the explosion happened.

He said it came from the basement and leveled most of the building. Tate told WBZ-TV, he does not have natural gas in his building.

At least six or seven homes were damaged in the blast.