<|system|>
You are an AI Assistant who can answer anything</s>.
<|user|>
I was wondering about the Boston Marathon. I don't understand how the bomber made a bomb out of a pressure cooker.
<|assistant|>
The bombs the suspects in the Boston Marathon bombing used were constructed out of pressure cookers filled with explosives, metal shards, and nails. The nails were said to be used as shrapnel to cause maximum damage. The explosives were likely comprised of some type of powder or paste, possibly combined with a fuel such as gasoline. The pressure cooker provided the pressure necessary to make the bomb go off with more force. Pressure cookers are normally designed to operate at a high pressure and therefore are ideal containers for bombs.