The Yogi Berra Museum and Learning Center at Montclair State University in New Jersey is now closed until further notice after professional thieves stole "several priceless pieces of memorabilia" on Wednesday morning.

The museum provides baseball exhibits and memorabilia for those who visit as well as educational programs for children that focus on sportsmanship and social justice. Sources told the New York Daily News that the thieves broke in through Yogi Berra Stadium, home of the minor league New Jersey Jackals, which is adjacent to the museum. County, state and federal agencies are investigating the burglary, but are not releasing any information just yet.

At this point it's not known what was stolen because the investigation is currently administering a full accounting of the museum to determine how much memorabilia/other materials is missing. The Essex County Crimstoppers program is offering  up to $5,000 for any information or knowledge of the burglary, but the good news is that these thieves will have trouble selling whatever was stolen, according to sports memorabilia expert Rob Lifson.

"This is very unique material and it would have to stay underground," Lifson said, via this Bleacher Report article. "These are not mass-produced items...it's like trying to sell a famous painting. Anyone who bought them would have to keep it secret. Why not just steal the Mona Lisa and try to sell that instead?"

What's on display in the museum? Dozens of baseball cards, two of Berra's MVP Awards, all 10 of his World Series rings he won as a catcher for the New York Yankees, a jacket he wore before throwing out the first pitch prior to Game 1 of the 2009 World Series, broken bats from former legends such as Gil Hodges, Duke Snider, Willie Mays, Stan Musial and Ralph Kiner, and much more.

UPDATE: The New York Post reported the thieves stole several World Series rings, two of Berra's MVP plaques, among other items. The rings are estimated to be worth $150,000 apiece and the plaques are between $100,000 and $250,000.

"All of the [memorabilia] dealers are very connected so I don't know how anyone could sell them," added David Kohler, owner of SCP Auctions. "It's a very significant collection and this is a big loss to the Berra family and the game of baseball."