Most Walmarts in the U.S. will stay open overnight on Thanksgiving to prevent overcrowding.  The flow of customers through the stores and the handling of limited quantity doorbusters is also being changed.  Black Friday sales will begin at 5 a.m. on Friday. 

The steps are being taken to avoid the overcrowding that led to the trampling death of a temporary worker at a New York store on Black Friday last year. 

Disney Stores will also be open in the wee hours, with over 100 of its 200 stores planning to open at midnight.  The remaining stores plan to open at 5 a.m.  Disney Stores will be discounting most store contents by 20%, plus offering one day sales.