Sentence 1: The U.S. Capitol was evacuated yesterday after authorities detected a possibly hazardous material in the basement of the Senate wing, Capitol Police said.

Sentence 2: U.S. Capitol Police evacuated the Capitol yesterday after a sensor detected a possible biohazard in the Senate wing, but authorities later said it was a false alarm.

From 0 to 5 (0="no meaning overlap" and 5="means the same thing"), how similar are the two sentences?
3