Experts were trying to determine Thursday how a piece of bread made its way into the Hadron collider in Switzerland, shutting it down for a couple of days.

The collider, a circular installation with a circumference of 17 miles, had already been delayed by a helium leak and is gradually being restarted. Scientists shut the collider down after noticing temperatures were rising Tuesday, The Times of London reported.

An inspection revealed a piece of baguette, the classic crusty long French loaf, had made its way into an electrical unit that should have been powering the cryogenic cooling unit.

A spokeswoman for the European Organization for Nuclear Research said the errant baguette would have had trouble getting over the security fences.

"Nobody knows how it got there. The best guess is that it was dropped by a bird, either that or it was thrown out of a passing airplane," she told the Times. "Obviously this was slightly surprising. Within the team there was some amusement once they had relaxed after initial concerns."