Hurricane force winds tore into the side of the backhoe loader factory in Rocester, Staffordshire, causing a wall to collapse and windows to fall to the ground.
Production was halted for 30 minutes for safety checks to be carried out. Clear up operations then began and the area beyond the wall declared safe for production to continue. No-one was injured in the incident and the area has now been cordoned off.
A JCB spokesman said: “Shortly after midday the skies blackened and powerful winds moved in, literally whipping up big waves on the lake at the front of the factory. Employees who have been here for decades said they had never seen anything like it.”
JCB backhoe assembly manager Richard Williams said: “I was about 30 yards away at the time and I heard an enormous crash. I turned around and saw the wall and the windows had come out and a big whirlwind of leaves and branches blowing around outside. Luckily no-one was in the vicinity at the time.”