The Petit Le Mans has been red-flagged just short of half-distance after lightning struck over the circuit.
The race was already running under a prolonged yellow as the early rain had returned with a vengeance, and with conditions worsened and the storm set to increase, the officials have elected to bring proceedings to a temporary halt. The clock will continue running during the stoppage, so the race will still finish just after 9pm local time.
This is the first time during the race's 12 years that it has had to be red flagged, and there are concerns that it might not be possible to restart unless the weather improves. The latest indications from race control are that the stoppage could last for around two hours, with 6pm local time the earliest racing is likely to resume.
Peugeot holds a one-two at present, with Franck Montagny in the #08 car leading Pedro Lamy. Early leader Allan McNish is right behind them in the #2 Audi, having spun back to third when he lost control on the slippery track during a previous yellow.
Marco Werner escaped a trip through the gravel to retain fourth at present in the other Audi, ahead of the ORECA and the Highcroft Acura.
The #16 Dyson Lola-Mazda would be leading LMP2 by a vast nine-lap margin if it was not ineligible this weekend as it tried a new bio-butanol fuel that the team is eyeing for 2010.
The rest of the LMP2 field has been delayed by various incidents. Marino Franchitti, Ben Devlin and Butch Leitzinger officially lead the class in the second Dyson car, despite losing time with an early gearshift actuator problem and a spin by Leitzinger.
Fernandez Racing's Acura lost a lot of time having steering problems attended to in the paddock, while the Cytosport Porsche was similarly delayed when electrical issues struck following Klaus Graf's spin through the sodden grass in the first hour.
GT2 has seen an incredible lead battle featuring between four and six cars all day, with the factory Corvettes invariably at the front.
But just before the stoppage the Risi Ferrari jumped from the tail of the lead pack to hold a one-lap advantage over the field having changed to wets under yellow just before the rain arrived.
The #92 Rahal Letterman BMW is second ahead of the Farnbacher Loles Porsche, the #4 Corvette and the #45 Flying Lizard Porsche, with the #3 Corvette a further lap back after Johnny O'Connell went off during the downpour.
Rob Bell also spun the Drayson Lola-Judd in the wet, but by that time the new car was already a long way down the field following an early crash for the former Le Mans Series champion.