Three thieves broke into France’s Musée Lalique in the early hours of July 5 and stole 27 pieces of jewellery and art valued at about $5 million. The museum, located in Wingen-sur-Moder, was closed at the time.

The burglars smashed their way through six display cases and removed works by French designer René Lalique. Among the stolen pieces was the museum’s “Woman Dragonfly With Open Wings,” a gold, diamond, and enamel pendant made between 1898 and 1900. It was the first piece acquired for the museum when plans for its creation began.

The thieves were inside the museum for about 11 minutes before escaping. Their haul included brooches, necklaces, bracelets, and other Lalique works. The stolen collection is valued at about €4.5 million. None of the pieces has been recovered.

France’s gendarmerie, a branch of the French Armed Forces, is investigating the burglary. The museum remains closed while officials review its security and prepare upgrades.