Vehicle suddenly lost power at 70mph in heavy traffic. This was after a very brief flash of the electrical system off and then back on. Vehicle was safely pulled to the side of the road (luckily). The electrical system kept demanding to âpush start❠and then would shut off and then immediately come back on, but without the engine starting. The vehicle would not completely turn off, or turn back on from that point forward, killing the battery in the process. We called Onstar, who had it towed to Bill Estes Chevrolet in Carmel Indiana. Mark in the service department then informed us that the engine was completely seized up and would require an engine replacement.