was impacted and began to smoke and emit sparks after rotation. In the other case, the battery pack that was crashed-tested one week earlier and that had been monitored since the test caught fire. The NHTSA then took an uncommon step on November 25, 2011, and opened a formal safety defect investigation "without any data from real-world incidents" to examine the potential risks involved from intrusion damage to the battery pack in the Chevrolet Volt. After the initial Volt fire, the NHTSA examined the Nissan Leaf and other plug-in electric vehicles and said its testing "has not raised safety concerns about vehicles other than the Chevy Volt." As a result of this investigation, GM announced that it would offer any new GM car in exchange to any Volt owner who has concerns while the federal investigation was taking place. In December 2011, the company said that if necessary they were prepared to recall all the vehicles and repair them upon determination of the cause of the fires, and also announced they would buy back the car if the owner was too afraid of the potential for a fire. GM's CEO also said that it may be necessary to redesign or make changes to the battery pack depending on the recommendations from federal officials. As of 1, 33 December Volt owners in the U.S. and 3 in Canada had requested a loaner car. As of December 5, General Motors reported that a couple dozen Volt owners had requested the carmaker to buy back their cars, and the company had already agreed to repurchase about a dozen. Before the carmaker agrees to buy back each vehicle, other options are explored as GM primarily wants to provide loaner cars, but "if the only way we can make them happy is to repurchase it, then we will," a GM spokesman said. General Motors explained that the buy back price includes the Volt purchase price, plus taxes and fees, less a usage fee based on how many miles the car has been run. As of January 5, 2012, GM reported that around 250 Volt owners had requested either a loaner vehicle or a potential buyback. The NHTSA also said it was working with all automakers to develop postcrash procedures to keep occupants of electric vehicles and emergency personnel who respond to crash scenes safe. Additionally, NHTSA advised to be aware that fires may occur a