The cause of a partial building collapse at an empty storefront at 1424 Wisconsin Ave. remains unknown after Department of Consumer and Regulatory Affairs work crews investigated the site Wednesday.

Helder Gil, public information officer for the DCRA, said that the inspectors had not yet determined the reason for the collapse because of large amounts of rubble at the site.

“The initial report … was that the collapse was caused by a gas leak, but as far as we can tell that was not the case,” he said.

DC Fire and Emergency Medical Services responded to the collapse on Thursday afternoon after being contacted by an unidentified person.

Oscar Mendes, acting public information officer at DC Fire and EMS, also reported significant damage to a vacant building at 1422 Wisconsin Ave., which neighbors the collapsed building. The building at 1426 Wisconsin Ave., which houses Major, a clothes and shoes retailer, also sustained some damages.

The Metropolitan Police Department was also called to the scene of the collapse to assist in closing off a portion of the street for pedestrian safety, according to public information officer Anthony Clay. Neither DC Fire and EMS nor MPD reported any injuries.

Work crews visited the site on Wednesday, but Gil said that he could not estimate when the cause of the collapse would be determined. He added that the site is too dangerous to perform thorough investigations until the rubble is safely removed.

“It really depends on how fast and how safely we can [remove the rubble],” Gil said.

The building at 1424 Wisconsin Ave. was due to be partially torn down before it was damaged in the incident last week. The demolition permit was issued earlier this year and is set to expire on Aug. 16, 2012, according to Gil.

The permit was granted to M Street Five Limited Partnership, with an owner address listed as Axent Realty Group in Potomac, Md.  Axent Realty owns several shops in Georgetown and commercial properties in both Maryland and Virginia, according to their website.

Gil said that none of the buildings have been condemned and that the damage appeared to be limited to 1424 Wisconsin Ave. and the two adjacent properties at 1422 and 1426 Wisconsin Ave.