ST. LOUIS (AP) — St. Louis police are trying to figure out exactly what thieves plan to do with hundred-pound terra cotta theater masks stolen from outside the old Sun Theater on Grandel Square.

Fifteen of the giant masks were taken sometime between July 12 and July 16.

Officials say they were removed from behind a locked construction fence at the Sun, which is in the midst of an $11 million renovation.

Twenty-nine of the masks had been taken down as part of the renovation. The Lawrence Group, which is rehabbing the Sun, had donated half of them to the City Museum.

But when the museum went to pick up the masks, they were gone.

The masks are worth $1,000 to $5,000 each — but they aren’t easy to sell.