San Jose Earthquakes were given a rude awakening at training this week when a Bradley Fighting Vehicle defence tank crashed into a wall just behind their facility.
The accident occurred on the barrier between the Quakes training ground and a test track for multinational defence force BAE Systems of Santa Clara.
San Jose goalkeeper Jon Busch admitted he was stunned when he heard the collision while taking in some training drills.
"I'm just glad it didn't come through the freaking fence," said Busch.
Quakes president Dave Kaval said it was extremely lucky nobody was hurt: "An incident like that could be really dangerous."
BAE's senior manager of external communications suggested speed was not the factor for the crash and was pleased that nobody was injured.
"No one was harmed and no damage was caused other than to the safety barrier," said Stephanie Bissell Serkhoshian.