Movie ticket sales traditionally dip between the blockbusters of summer and the Oscar contenders of winter, but last weekend’s crop of new films took the tradition to a startling new low — delivering the lowest total box-office gross since the weekend after 9/11, despite two new wide releases (the romantic thriller The Words and the action flick The Cold Light of Day). Why did audiences shun the megaplex this weekend? Here, 4 theories:

1. Blame the back-to-school season
"People are getting their life back in order after the summer, and movies aren't part of it," Steven Friedlander, the executive vice president of theatrical distribution for CBS Films, tells the Los Angeles Times. At the beginning of fall, parents and their kids are "doing back-to-school shopping" or getting ready for the dorms, which makes going to the movies low on the weekend priority list. Unsurprisingly, given the timing, ticket sales for The Words — the highest-grossing new release — came mostly from "older women."

2. Blame the Aurora, Colo., shootings
The weekend's release schedule had a gaping hole "due to Aurora," says Tom Brueggemann at IndieWire. The Ryan Gosling drama Gangster Squad, a much-hyped picture originally scheduled for release last Friday, was delayed because one of its scenes shared "eerie parallels" with the shooting at a midnight screening of The Dark Knight Rises in Aurora, Colo., last July — and had to be re-shot. If Gangster Squad had hit theaters as originally intended, the weekend box-office "would likely have met the level of other recent years."

3. Blame the yawn-worthy movies
It "really isn't rocket science," says Ray Subers at Box Office Mojo: Audiences won't pay to see bad movies. Studios can blame "the beginning of the school year" or "the start of the NFL season," but external factors can't completely account for the worst box-office revenue in a decade; instead, blame the studios themselves for "two lousy new releases and a handful of mediocre holdovers" — insufficient fodder to convince people to "leave their homes, travel to the theater, and drop $8 a ticket."

4. Actually, the box-office was fine — just not for new studio film
The otherwise dismal weekend boasted a few "bright spots," says Erica Orden at the Wall Street Journal, but they were "less conventional" releases than studio films like The Words and In the Cold Light of Day. 2016: Obama's America, a "low-budget documentary critical of President Barack Obama," had another stellar weekend, and a limited IMAX re-release of 1981's Raiders of the Lost Ark, the first Indiana Jones film, earned $1.8 million on just 267 screens nationwide.