"The Lego Movie" built on its previous weeks' success atop the North American box office for a third weekend in a row, earning $31.5 million, industry estimates showed Sunday. The Warner Bros animation movie, which is based on the popular kid's toy, made it look like child's play: it has raked in $183.2 million since its opening, box office tracker Exhibitor Relations said. "3 Days to Kill," an action-thriller starring Kevin Costner as a secret agent tasked with one final, deadly mission, debuted at second place, pulling in $12.3 million despite mixed reviews. It was followed by "Pompeii," another new entry at the box office, which enjoyed estimated ticket sales between Friday and Sunday of $10 million. Set in 79 AD, the film tells the story of a lovelorn slave-turned-gladiator. The latest version of cult classic "Robocop" was down one spot to fourth with a weekend $9.4 million, meaning it has now gobbled up a total $43.6 million since its release on February 12. George Clooney's true drama "The Monuments Men" was another that dropped, one place to fifth, with sales of $8.1 million, for a total $58.1 million since release. "About Last Night," a romantic comedy starring Kevin Hart, was a close sixth, with $7.4 million in box office sales. Lagging behind in sixth, with a $4.7 million take, was a police action-comedy starring Kevin Hart -- his second appearance this weekend in the top 10 movies -- and Ice Cube. Disney smash and animated Oscar nominee front-runner "Frozen," loosely-based on a Hans Christian Andersen fairy tale, held onto the eighth spot in its 13th week in theaters, with $4.4 million. And rounding out the 10 most popular movies in the United States and Canada were "Endless Love," with $4.3 million, and "Winter's Tale," with $2.1 million.