Crews working to contain toxic smoke and runoff from 4-alarm fire in San Jose

SAN JOSE (KGO) -- Huge flames and dangerous chemicals created a massive environmental nightmare in San Jose overnight.

Firefighters are trying to make sure there are no flare ups. Workers in dozens of businesses could be let back in soon, but not before a toxic mess is cleaned up.

The four-alarm fire was reported at 12:30 a.m. at Haro's Metal Finishing on Reynold's Circle near Zanker Road. It took firefighters about an hour and fifteen minutes to get it under control, but the flames weren't the biggest danger facing firefighters.

"They would use things like sulfuric acid, zinc, other zinc oxide and other things like that to do etching and that type of cleaning of metal. And so those were the chemicals that we think were initially involved. But with this volume of fire it kind of a made a chemical soup," said San Jose Fire Capt. Mike Van Elgort.

That chemical soup pooled around the commercial buildings creating a massive hazmat situation. That combined with the toxic smoke forced about half of all the firefighters on the scene, around 50, to be decontaminated. Fire officials say it appears no firefighters were injured. And amazingly, the fire was kept to the one commercial building.

"Glad our business didn't get caught up in it. Sorry for theirs. Glad too many people around here didn't get affected," said Steve Contratto, CF Sales.

The business owners are responsible for the clean-up of the contaminated run-off. But while insurance agents and private environmental clean-up companies got involved -- several businesses in the area were blocked off. Dozens of workers were left waiting.

"We have 11 orders today. We have to call the clients and cancel it and we'll see what the clients are going to say. It's upsetting," said Semyh Gun, Caterman catering.

A ladder truck was contaminated by the toxic water and will be out of service -- until it can be cleaned up. As for the cause of the fire -- investigators will have to wait until it's safe to go inside before they can determine what started this fire.