The starting line and burnout box of a drag strip are a rather dangerous place, and you have to be on high alert for wayward cars and even parts at all times. Being in such close proximity to the racecars can be exhilarating, but there is a high level of danger that comes with that thrill as two spectators found out at the Racing On Rucci donk drag racing event at Cordova International Raceway this weekend.

The burnout box might seem relatively safe since cars aren’t moving at a high rate of speed, but there is still a possibility for danger due to flying foreign objects. Racers who came to Cordova International Raceway for the Racing On Rucci event were trying to pick up the $5,000 purse on the line, so they all had their cars set on kill.

Sage Thomas, also known as Donkmaster, was getting ready to square off against Turbo Joe in his G-Body during the event when things went terribly wrong: the 1971 Caprice driven by Thomas began to do its burnout when the stock harmonic balancer failed on the turbocharged engine, sending pieces flying into the crowd lining the burnout box.

Around the 23-second mark in the video after the burnouts begin you can see parts begin to fly out from underneath the Caprice. The two individuals who were struck by the balancer debris experienced significant facial injuries — one with multiple low jaw fractures and other injuries requiring surgery, and the other with significant lacerations on his head. We wish both individuals a speedy recovery after this terrifying incident.

Jump to 10:08

According to JC Beattie Jr. from ATI Performance Products, a highly modified stock engine should never be equipped with a stock harmonic balancer, because they aren’t made for those sort of extreme conditions.

“Stock dampers are made from very weak cast material and are not made to do any more than protect the engine in its stock build from the manufacturer and to last past the warranty period. OEM dampers have no place on modified engines at a race track.”

Fast forward to the 10:13 mark