Company i work for is charging me money for a mistake??? HELP!!?

ok, here's the story.... i work for a distribution center, small company in the state of CA....im a forklift driver and one day, a load that i loaded, on its way to its destination it fell all over the place, when it got to its destination, they returned it........ now the company wants me to pay the charge backs they got..... they said they would pay half and i had to pay the other half... WHAT THE HELL!!!!. IS THAT LEGAL TO DO???... isnt that the risk a company takes when hiring workers?? they win some lose some??? how does it work?? PLEASE HELP!!! too much money to pay//