In Virginia, a spectacular Union attempt to break the siege of Petersburg ends in disaster in "The Battle of the Crater"

With trench warfare around Petersburg, Virginia stalemated, Union forces planned to blow up a section of Confederate line and make a breakthrough infantry assault.  Weeks of tunnelling by Pennsylvania troops placed around 8000 pounds of explosives twenty feet below enemy positions.  Before dawn, the resulting blast blew a massive crater into which Union infantry charged.  The attack became a disaster as Confederate reinforcements closed the line, firing down on the Union infantry, which lost more than 3500 men.  (By John Osborne)