Ten-man Sunderland had a night to forget after suffering their second league defeat of the season in stunning fashion.
A hat-trick from Kevin Nolan and a brace from Shola Ameobi helped Newcastle to their biggest home victory over their local rivals for more than half a century.
Sunderland, who scored a late consolation through striker Darren Bent, had defender Titus Bramble sent off eight minutes after the restart when Newcastle were already 3-0 up.
"It's pure disappointment. We've got a group of people who will have to apologize," Bruce was quoted as saying on Sunderland's official website after the game.
"No excuses. We were beaten well and truly. We were naïve and didn't handle the occasion at all.
"Everything which could have gone wrong went wrong. We all have to live with this - it hurts.
"To witness that is difficult to take and there'll be a few - me included - who have a repair job and rightly so. My message to the fans is - we apologize."
Egyptian wing-back Ahmed Elmohamady maintained his 100% appearances in the Premier League but was substituted five minutes before the break, making way for Ghana striker Asamoah Gyan.