Crews in protective gear tackled the foam with a defoaming agent, then vacuumed up the liquid left behind. Santa Clara city workers helped with the storm drains.
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"Started dropping the sandbags in the storm line, stopped it up, made a dam so that it didn't go any further," said Jack Miller, a heavy equipment operator with the City of Santa Clara.
Just before 11 a.m., the fire suppression system inside the hanger went off, filling the entire building with firefighting foam. It oozed from the vents creating a deep sea of bubbles the size of a city block.
"If there had been a fire, we'd all be congratulating them on a well-designed system," said San Jose Fire Department Capt. Mitch Matlow.
But that was not the case and the fire department had concerns about chemicals.
VIDEO: Mountains of foam flood Santa Clara street
"I don't advise you to go play in it like bubbles in the bathtub," Matlow said.
A cyclist couldn't resist.
"In the middle, it's probably like 10 feet tall," said cyclist Blake Harrington.
As a concentrate, the Aqueous film forming agent is a carcinogen and irritant. It's technically safe in foam form, but San Francisco Baykeeper is worried about wildlife.
"It seems reasonable to expect that some of it will make its way into the creeks and the Bay," said Ian Wren, a staff scientist with san Francisco Baykeeper.
It was a serious situation and a popular attraction.
"I'm from Wisconsin, so I know what snow is like. I miss it." Said Jenevieve Dreyer.
"Looks like a huge foam party gone bad," said Baldomero Aguilar.
The owner of the hanger, Signature Flight Support said there were no people or planes inside at the time and they believe it was a mechanical issue.