Factual error: If the natural gas could be rerouted to McClane's position at the national grids control center, there are two major problems. The gas would not self-ignite on its way there as pictured, and the sheer momentum of that massive amount of gas in those long pipes would cause a massive leak at the endpoint. However, after the first (relatively small considering the total energy in all the gas) explosion, everything goes back to normal without one giant amount of gas erupting.
Andreas Winnberg
2nd Jul 2007