Hoping to rebound from their Week 1 divisional loss to the Ravens, the Steelers played their home-opener against the Seattle Seahawks at Heinz Field. After a failed 4th and goal run on their first drive, Pittsburgh delivered the game's first punch with a 1-yard touchdown run from running back Rashard Mendenhall. This score on their second drive gave them the early lead.  The Steelers added onto their lead in the second quarter with a 20-yard touchdown run from running back Isaac Redman, followed by a 20-yard field goal from kicker Shaun Suisham.  Pittsburgh's offense made one last score in the third quarter with quarterback Ben Roethlisberger finding wide receiver Mike Wallace on a 2-yard touchdown pass.  From there, the defense prevented any scoring attempt from Seattle's offense.
How many touchdowns were scored in the first half?
2