While many Americans are going back for seconds this Thanksgiving, others will be jetting out of the house to take advantage of massive holiday sales, some of which even begin Thanksgiving night. Department stores and retailers across the country have huge sales events, creating massive lines waiting for the doors to open.

The frenzied crowd of consumers is a well-known phenomenon, but large crowds at special retail sales and promotional events pose an increased risk to employees. Overcrowding, rushing, struck-by incidents, potentially violent acts and even fires are some of the scenarios that can result from the mixture of holiday enthusiasm and large groups.

In 2008, for instance, a retail worker was trampled to death as a mob of shoppers rushed through the doors of a large store to take advantage of a Black Friday sales event.  The Occupational Safety and Health Administration (OSHA) has issued safety guidelines to prevent this type of tragedy, and we at  OSHA urge retailers to adopt a crowd management plan during the holiday season to prevent employee injuries and needless deaths.

To start, a crowd management plan should be developed and implemented in advance of events that are likely to draw large crowds in order to protect employees from crowd-related injuries. Workers are best prepared for such events when employers also incorporate pre-setup and emergency situation management in their plans.  Such plans include having trained security personnel or police officers on site, erecting barricades or rope lines for pedestrians that do not start at the store’s entrance, putting emergency procedures in place that address potential dangers, and explaining approach and entrance procedures to the arriving public.

Even after the rush outside has dissipated, a crowd management plan should direct store managers to heed the maximum occupancy level inside the stores and control the entrance of additional shoppers. Exit doors must not be blocked or locked. Unless such measures are implemented, an ill-prepared crowd management set-up increases the risk for tragedy.

As we enter the busiest shopping season of the year, retailers should prepare for increased consumer activity while maintaining their standards of service. With so many people drawn together in tight quarters, it’s critical that retailers ensure a crowded environment remains safe for all. The holiday season ushers in the spirit of joy and community for those around us. At OSHA, we want everyone to get home safely each and every day. And that is something to be grateful for.

David Michaels is the Assistant Secretary of Labor for Occupational Safety and Health.