Arguably the most dangerous thing that a forklift operator can do is to turn on full lock at maximum speed. With the exception of certain trucks, (such as the Still R70 or Toyota machines fitted with their System of Active Stability) turning sharply at speed is almost guaranteed to turn the truck over sideways. Ironically this situation is made worse when the truck is not carrying its load. The reason for this is that the weight of the load, when being properly carried, is transferred to the front wheels of the truck and tends to hold them in greater contact with the ground than would be the case with an unladen truck. Turning at speed is regarded as a highly dangerous practice regardless of whether or not the truck is laden.
You may have seen people doing this and getting away with it and wondered why? The next few slides go some way to explaining this.