PORTLAND, Ore. -- The investigation into what caused a massive gas leak explosion on Northwest 23rd Street in Portland ground to a halt Saturday, after asbestos was discovered on the site.

The huge backhoe clearing debris went silent mid-morning, and workers were ordered to stop digging through the rubble.

Background: Gas leak causes explosion, extensive damage in Portland

For nearby businesses, it was the latest bad news to come since Wednesday's explosion.

"It raises the level of how dangerous this zone is that we're in,” said Deborah Haynes, who owns Blush Beauty Bar.

The blast blew out the windows of her shop and covered her merchandise with grit, and now she's wondering if asbestos came with the dust.

"My whole store is covered," she said.

According to the Oregon Department of Environmental Quality, asbestos was found in roofing material at the site. Backhoe operators wore face masks earlier in the day.

There is no health risk to the public, according to DEQ. Asbestos fibers, when breathed in, can cause cancer.

Because of the delay, Haynes and other merchants got more bad news: The opening of the block, and the return of customers, may not happen this weekend.