Too many stupid things

Demasiadas tonterias juntas

The movie starts well and has special effects just right but it gets very bad

You can't cause a worldwide eruption like that, and it would need weeks too propagate.

Any poissonous gas would have entered into the bus.
CO2 is not poissonous, and it dissipates.

Stones don't fall just on the characters just when they move, as if they were shot by a cannon.

Titanium is not a good isolator (in fact it's a good conductor) and melts very easily compared to other elements or composites.

Americans try to solve everything with weapons and explosions. An explosion would make everything worse.

They don't need to carry the bomb with a person.

The explosive wouldn't stand that temperatures for 3 minutes.