After their first full day of examining Main Street’s fire-ravaged buildings, Austin Fire Chief Dan Wilson said they still have not determined a cause.

“The cause-and-origin investigation is not complete and is still under investigation,” Wilson said briefly this morning.

Investigators picked through the ruined husk of what was the clothing store on Main Street, the first building taken by the fire. The investigators wore protective clothes and air-filtering masks to protect them from asbestos. A building was cordoned off by tape warning of the hazard.

“There’s a respiratory hazard,” State Fire Marshal Steve Wolf said Wednesday.

Though there is no cause or origin yet, the investigation has been steady.

“It’s been smooth once we got through the hard stuff,” Wolf said, referring to the covering of ice over the structures.