Car turns off when driving and sometimes cannot be restarted

This has happened twice so far. the car turns off and I cannot restart it. A mechanic lookked at it the next day and it started right up after charging the battery since I kept trying to crank the engine the battery ended up low. They thought it could be low on fuel as diagnostic testing was inconclusive. Now it happened again where I cannot restart it and a buzzing sound I heard the first time coming from the front Iam hearing again. It appears to be coming from the integrated control module. Could that be causing this. It did turn off once between these two instances, and I heard the same sound, but was able to start the car back up just fine and had not had the issue until now.