The atomic bombing of Nagasaki was exactly three days after the bombing of Hiroshima.  It took place on August 9th, 1945.  The bomb that they dropped during this attack was named Fat Man and it was a plutonium bomb.  The main target was Kokura Arsenal.  In Kokura there were many war industries.  The second target that they were aiming for was Nagasaki.  The aircraft commander was Major Charles W. Sweeney.  There were nearly 200,000 people in the town before Fat Man exploded.   Nagasaki is the city that ended up getting the bomb.  Fat Man did explode with more force than the Little Boy the damage was not nearly as bad as Hiroshima.  

The total amount of killed and injured was nearly 100,000.

http://www.cfo.doe.gov/me70/manhattan/nagasaki.htm