Eric Richardson / blogdowntown

Cars pass a darkened Staples Center in Downtown Los Angeles on October 10, 2011.

DOWNTOWN LOS ANGELES — The NBA officially cancelled games through December 15 today after talks broke down and the player's union began the process of filing legal action against the league.

That means 24 regular season games have now been cancelled here at Staples Center, home to both the Lakers and Clippers.

Dark nights mean fewer visitors to Downtown and an economic hit for the neighborhood around the South Park arena. Last month, economist John Black estimated that a 30 game stoppage could equal $40 million in lost economic activity for Downtown.

Arena owner AEG has been able to fill a few dates, however.

Last week, Katy Perry announced that she would be adding a free date at Staples Center on November 23, the day after her scheduled sold-out show at the arena.

Today, a third night was added to December's "Watch the Throne" tour with Jay-Z and Kanye West. Originally scheduled to play just one night on December 12, the tour had already picked up a second date on December 13. Now tickets will go on sale Friday for a show on December 11.

That won't pick up the NBA slack, however: December 11 was scheduled to be a doubleheader at Staples Center, with the Clippers playing the San Antonio Spurs at 12:30pm and the Lakers taking on the Orlando Magic at 6:30pm.