When fireman Gordy Brewer's (Arnold Schwarzenegger) wife and child are accidentally killed by a terrorist's bomb, Arnie travels to the jungles of Colombia on a quest for revenge. He has no gun, no discernable plan, and no hope of blending in with the local fun-loving populace who dabble in homicide for amusement and make their living kidnapping Americans and ruthlessly dealing drugs. To his credit, Arnie does, however, have a gift for both arson and dumb luck.

Miraculously, Arnie not only locates the bad guy but almost blows him up with a makeshift bomb fashioned out of the materials on hand. If only Arnie hadn't been morally obligated to save the terrorist's wife and child at the last minute, he could have gone home early with the sweet taste of success. Instead, he gets captured and mistreated. The terrorist's wife eventually helps him escape (no thanks to the CIA) but not before the terrorist has gone back to America to do another bomb job.

This eventually leads to a final showdown in a tunnel under the CIA building. The terrorists are about to escape on a motorcycle, and Arnie closes an automatic gate near the end of the tunnel to prevent it. Realizing the terrorists will return, he sets a trap. Using a fireman's ax he punches numerous holes in two different four-inch-diameter natural-gas lines and runs back through the tunnel supposedly toward safety.

In reality, if he had actually punched holes in the gas line the action of a steel ax striking a steel pipe would have probably created a spark and ignited the gas. Sparks of this type are very hard to see with normal lighting but frequently occur when steel strikes steel.

The terrorists ride straight through the gas cloud while firing a handgun at Arnie. This is not overly bright since it sets off the gas. Evidently, the moviemakers were also not overly bright in physics. The gas cloud doesn't explode until the terrorists have ridden some distance beyond it. When it does explode the terrorists have plenty of time to look behind them, do a dramatic double take, and then attempt to outrun the fireball. They are finally engulfed by the flames but later emerge to be killed yet again in the usual encore chop socky round with Arnie. (Gosh, we never saw that one coming.)

Confined gas-cloud explosions similar to the type that Arnie created have blown craters in the ground and destroyed entire buildings. Explosions of this type are used in military munitions with devastating effect. Typical flame velocities in military fuel-air explosions are about 1800 m/s, not exactly easy to outrun. However, if the bad guys set off the explosion by firing a handgun it means they were in the gas cloud. There would have been no chance to outrun it. They would instantly have been engulfed in flame.

The terrorists would not only have been incinerated, but been blown to bits. Military fuel-air explosions usually occur in open spaces, yet they produce pressures of about 19 bars or 276 psi. This would subject a hapless human standing in the path of the pressure wave to a bone-smashing force of nearly 300,000 lbs (1,330,000 N). A similar explosion confined in a tunnel could produce even higher pressures. Someone in the middle of the explosion would be lucky to have a pulse, let alone a Tae Kwon Do match afterwards.

Okay, maybe there wasn't enough gas leaked before the explosion to demolish the CIA building. However, the fire afterwards would have been an inferno. The blast would have blown open firedoors in the stairwell to the tunnel, and the CIA building would have acted like a giant chimney for the fire fed by the gas lines.

When the gas lines got hot enough the steel in them would have lost its tensile strength, expanded, and exploded like a balloon. Depending on the nature of the flame pattern this could have happened in minutes. The resulting explosion would have completely ruptured the lines and sent a second very nasty fireball down the tunnel.

The only way to stop the inferno would have been to close the gas valves some distance from the fire. Even with the valves closed the gas line would have taken a long time to de-pressure. Once started, the fire would probably have burned for hours. It's hard not to love the big guy, but with a hero like Arnie, who needs terrorists?