This USA Today article describes a recent tragic accident where a digital signage pedestal tipped over and crushed a young boy.
While not a 'surveillance' equipment incident, many security companies are tasked with hanging similar equipment and certainly heavy items over head.
The reminder to all of us: make sure than our mounts and installations are hung to spec and no corners are cut. The aim of our systems is to keep people/property safe, not endanger it!
See YouTube clip of the accident below: