A mysterious giant foam blob is filling up a street in Santa Clara, California. KTVU Fox 2 is on the scene.

The blob was for a time a mystery, with law enforcement unable to explain it. But the Santa Clara Fire Department has Tweeted an explanation: a malfunctioning fire suppressant system. Workers on the scene have been seen stacking sandbags.

We echo KTVU’s sentiment: Sit back, relax, and mash the WOW! button as it grows.