ALLENTOWN, Pa. -

Allentown fire officials have ruled the Memorial Day blaze on the city's East Side was accidental in nature, but investigators literally have to do more digging to find the source of the fire.

They need to bring in a backhoe, said Capt. John Christopher of the fire department, but that probably won't happen until Monday.

The big fire broke out just after 4 p.m. this past Monday at RDM Enterprises, 1302 Irving St., behind Woodlawn Memorial Park.

The business makes and finishes parts for violins and other instruments.

A fire wall kept the flames out of an adjoining business, Consolidated Carpet Mills, but rugs worth thousands of dollars were ruined.

The fire re-ignited on Thursday morning, producing smoke, but quickly was brought under control.