Here is my take on this.
Nancy was throwing a consolation party for Trump's supporters and to make it a fun event, she encourages them to wear costumes. Sadly the party got out of hand when they found out the Trump was not invited and they proceeded to trash the place. Nancy called 911 and no one answered because its was a day off for the Capitol Police. In desperation she called the White House to ask Trump to come over, but Trump was busy packing the classified documents for his trip to Florida, so he said no can do.
So in the end who caused the storming of the Capitol? Nancy for throwing her party.
Why did the place the trashed? Capitol Police were off duty that day.
See this was all a big misunderstanding form a party gone wild.
