On Sunday, Nov. 17, two people were critically injured and three firefighters were hospitalized after an auto accident on Interstate 64 near the Jefferson County/Shelby County line in which a car rear-ended a fire truck that was on-scene in response to a rollover accident.

A 2011 report from the Kentucky Transportation Center analyzed crash data over an 18-month period and found that nearly 4 percent of crashes were categorized as secondary. Secondary crashes are those that are a direct or indirect result of a previous accident.

Not all states track secondary crashes, but those that do indicate that between 3 and 20 percent of motor vehicle accidents are secondary crashes. Secondary accidents can be especially dangerous to emergency responders coping with the aftereffects of initial accidents.

According to the Indiana Traffic Incident Management Effort (IN-TIME) effort, approximately 50 percent of all police, EMS and firefighter fatalities are due to transportation accident. The IN-TIME report also states “secondary crashes … are estimated to represent 20 percent of all crashes.”

The vulnerability of emergency personnel, in addition to helping maintain traffic flow, are why many states—including Indiana and Kentucky—ask drivers involved in crashes to move vehicles to the shoulder of the road if possible. For additional information on steps to follow in the aftermath of a wreck, please see What to do After a Car Accident.