CONSPIRACY theorists would have a field day with this one: the Large Hadron Collider (LHC), the particle smasher being built at CERN, near Geneva, Switzerland, suffered a serious setback when a support structure for key magnets failed during routine tests on 27 March. The magnet assembly was made by Fermilab, CERN's main rival in Batavia, Illinois.

The so-called inner triplet magnets are designed to squeeze the LHC's counter-rotating proton beams and make them collide at four points along the 27-kilometre tunnel. The magnets are cooled using superfluid helium at 1.9 kelvin inside a vacuum, but a structure holding the magnets in place broke when asymmetric forces of the kind expected during the LHC's operation were applied.

"It wasn't strong enough," says Fermilab's Peter Limon, who is now at CERN. He adds that "people are disappointed, of course, but there are no recriminations".

Limon is also concerned about a cryogenic box that feeds power and helium to the magnets, which was near the accident. "We have yet to determine if it's damaged," he says.