The Museum of Modern Art in Paris was robbed. Five paintings, worth at least $100 million and included works by Picasso and Matisse, were stolen Thursday.

According to investigations, the museum's alarm system had been broken since March 30. Apart from that, a sawed-off padlock was found and a masked figure dressed in black slipping through a broken window was captured by the security camera.

French authorities are puzzled how a thief could get through three guards on duty from the Art Deco-style Museum of Modern Art, which is just across the Eiffel Tower, and get away without being seen.

"We're dealing with an extreme level of sophistication," said Christophe Girard from the French capital's cultural affairs department.

While some were impressed with how the theft was done, others from the art world are focused on the museum management's negligence, particularly on its broken alarm system.

Tom Cremers, a museum consultant and former head of security at the Rijksmuseum in Amsterdam, said that the museum's director should be immediately terminated.

"It's unthinkable that your security system is not fully working for two months. It's like inviting the thieves in," he said.

In a statement, Paris Mayor Bertrand Delanoe said that the security upgrade done from 2004-2006 cost about $19 million. When the alarm system broke in March, a maintenance company was notified right away, however, the new equipment never arrived.

"I'm particularly saddened and shocked by this theft," Delanoe said.

The mayor added that aside from the detective work being done by a special police brigade, an administrative investigation of the crime is also necessary.

According to Girard, the robbery seemed to have taken place between 3 a.m. and 4 a.m. but was only discovered before 7 a.m. Thursday. Officials are looking into the possibility that an accomplice may have been involved.

Pablo Picasso's "Pigeon With Peas" (1912), Henri Matisse's "Pastoral" (1905), Amedeo Modigliani's "Woman With a Fan" (1919), Georges Braque's "The Olive Tree Neer I'Estaque" (1906) and Fernand Leger's "Still Life With Candlesticks" (1922) were the paintings stolen from the museum.