False Alarm

This morning a car was crashed this morning into the building that houses the PP headquarters, which is the political party that is in charge of the Spanish government. Fortunately, there were no casualties. At first the police had thought that it could have been a terrorist attack, but later on they dismissed that idea. On being arrested, the driver of the car driver claimed that he had a bomb in the car's boot that would explode within the next following forty-five minutes. The police cordonned off the area and evacuated the building, but they only found two butane canisters and a primitive home-made bomb. The officers who deactivated the bomb said that it was harmless.
The driver of the car turned out to be a 37-year-old unemployed man with psychiatric problems, not a terrorist as the police had thought.

False Alarm

A car was crashed this morning into the building that houses the PP quarters, which is the political party that is in charge of the Spanish government. Fortunately, there were no casualties. At first the police had thought that it could have been a terrorist attack, but later on they dismissed that idea. On being arrested, the car driver claimed that he had a bomb in the car's boot (trunk is more commonly used instead of boot) that would explode within the following forty-five minutes. The police cordonned off the area and evacuated the building, but they only found two butane canisters and a primitive home-made bomb. The officers who deactivated the bomb said that it was harmless.
The driver of the car turned out to be a 37-year-old unemployed man with psychiatric problems, not a terrorist as the police had thought.

This is very good and could pass for an article written by a native English speaker.

A car crashed this morning into a building that housed the PP quarters??. This is the political party that is in charge of the Spanish Government. Fortunately, there were no casualties. At first, the police thought that it could have been a terrorist attack, but later on they dismissed that idea. On being arrested, the  driver claimed that he had a bomb in the car's boot and that it would explode within forty-five minutes.

The police cordoned off the area and evacuated the building. They only found two butane canisters and a primitive  homemade bomb. The officers who deactivated the bomb said that it was harmless.
The driver of the car turned out to be a 37 year old unemployed man with psychiatric problems, not a terrorist, as the police had thought.

Primitive – es un poco raro en este contexto.
PP partido PP party.