When Nitrous Oxide explodes inside an engine it allows more oxygen and consequently more fuel to enter, creating more power. As you can see from this video—taken at the Yas Marina Circuit in Abu Dhabi—when nitrous oxide explodes outside an engine it can create a pretty massive explosion.
When we found this video on Bangshift.com, we initially thought the small nitrous backfire underneath the hood of this ProMod Camaro was the explosion in question—don't worry it isn't. After the initial fire, while the crew member is talking to the driver of the Camaro, we see what appears to be Nitrous wafting out of the front hood. Somehow shortly thereafter the starter is engaged—presumably by the driver—at which point all hell breaks loose.
We don't know exactly why the car was leaking laughing gas but trying to start a car post Nitrous backfire without knowing exactly what happened is certainly the kind of stupid decision that leads to the destruction of a new and expensive drag spec Camaro—as you can see. Luckily no one was injured when the car exploded.