Driving up snowy pass on I-90 approaching the top of Snoqualmie Pass. Vehicle stalled and warning lights flashed critical warning and loss of power. The vehicle stopped in the middle of the highway and would not start or go into drive. After a few minutes, because of speeding and adverse conditions, another driver collided with my vehicle from behind. Another following vehicle lost control and ran off the road. Nobody was injured. Mazda has not provided any information to what happened with the vehicle. We added about 12k miles in the 5 months of driving it, so we had lots of testing with it, and never ran into this serious of an issue with this or any other vehicle.