Context: Coming off their bye week, the Broncos stayed at home for a Sunday night intraconference duel with the Pittsburgh Steelers.  In the first quarter, Denver trailed early with Steelers QB Ben Roethlisberger completing a 1-yard TD pass to TE Heath Miller.  Denver would respond with QB Jay Cutler completing a 15-yard TD pass to WR Brandon Stokley.  In the second quarter, the Broncos took the lead with Cutler's 1-yard TD pass to FB Cecil Sapp, along with rookie DE Tim Crowder returning a fumble 50 yards for a touchdown. In the third quarter, the Steelers tried to come back with Roethlisberger completing a 13-yard TD pass to WR Santonio Holmes.  Fortunately, Denver answered with Cutler completing a 1-yard TD pass to TE Tony Scheffler.  In the fourth quarter, Pittsburgh managed to tie the game with Roethlisberger completing a 13-yard TD pass to TE Matt Spaeth and a 12-yard TD pass to Miller.  Fortunately, kicker Jason Elam came through for the third time this year as he nailed the game-winning 49-yard field goal.

Question: What was the longest TD pass?

Answer:
15-yard