A crash that killed a teenage brother and sister was so shocking, the first emergency responder on scene had a heart attack.

Eric Neibaur, 15, and his sister Lauren, 13, died in a head-on crash in the US state Idaho last Sunday. A rescuer – who has not been named – went into cardiac arrest while pulling their bodies from the crashed vehicles and almost died himself. He is understood to have been consumed with emotion at seeing the children’s corpses.

The emergency responder was rushed to hospital and has reportedly since been released. Eric and Lauren were driving a pick-up truck – driven by Eric – when it swerved into a the wrong lane and collided head on with another car, according to local media. Jay Lanningham, 70, who was driving the other car involved in the collision, was also killed instantly in the crash.