Northern Iowa cashed in those 19 turnovers into 15 points.
NIU doubled WSU's big men whenever they got the ball in the paint. The Cougs didn't pass effectively or draw a foul out of those situations -- Washington State didn't even get to the charity stripe until more than five minutes had gone by in the second half.
They finished 4 of 5 from the line while NIU went 19-23.
Meanwhile, NIU logged 11 steals against the Cougs. And Washington State's 59 points were a season low.
Still, Washington State held a lead late in the second half before being outscored down the stretch in a game where the lead changed 19 times. Que Johnson with a 3-pointer with about four minutes left to put the Cougars up 53-52..
"It is disheartening because we did a lot of things right; we shot the ball well, we rebounded the ball well, I thought we defended one of the best 3-point shooting teams in the country well — giving up only four 3s — but the thing we didn't do well was take care of the ball," Ernie Kent told the Associated Press after the game.
Washington State shot 49 percent (24 of 49) from the field compared to 42.6 percent (20 of 47) for Northern Iowa.
Josh Hawkinson led the Cougars with 14 points and 11 rebounds, his eighth double-double of the season and 28th of his career.
No other Cougar had more than three rebounds on the night. The Cougars still outrebounded Northern Iowa 31-20.
Ike Iroegbu scored 12 points on 4 of 13 shooting. Derrien King tied his career-high with 10 points (4 of 10).
Washington State faces New Mexico for seventh place in the tourney on Christmas morning at 10 a.m. Pacific. The loser of the game will go 0-3 in tournament play.