Secondary blast injuries are primarily caused by which of the following?

Secondary blast injuries are primarily caused by flying objects striking individuals. In the context of explosive incidents, these injuries occur when objects in the vicinity of the explosion are propelled by the force of the blast. As the explosive material detonates, it creates a shock wave and causes debris and shrapnel to be thrust into the air, which can then strike bystanders or individuals within the blast radius, leading to penetrating wounds, fractures, and other serious injuries.

While blast wave exposure does contribute to primary blast injuries and the shockwave can impact individuals, the secondary blast injuries specifically refer to harm inflicted by the debris itself. Other options like striking other casualties or falling from height may occur in chaotic environments following a blast, but they do not specifically characterize the mechanism of secondary blast injuries, which distinctly involve the impact from flying objects as a direct result of the explosion. Thus, the accurate identification of flying debris as the leading cause underscores the significance of situational awareness and protective measures in environments where explosions may occur.