If a car breaks down in the drive thru lane of a fast food place, would the driver be liable for lost business while waiting for a tow truck?
Liability in the sense that you're referring to would have to arise from some wrongful act on the driver's part, so the driver would have to have been negligent in some way. The first step is to establish that the driver had a duty to care about a forseeably damaging situation; then, did he knowingly put the restaurant at risk? The law does not hold you blanketly responsible if someone suffers a loss because of you, but it may hold you responsibly if the loss arises from you doing something that you should not have done. If you refuse to let them push your car out of the way (assuming no compelling justification), they would probably be on the hook, whereas if you were unable to push your car out of the way and they were unwilling, you probably would not be. There is no generic "duty to not drive a vehicle that might break down". At a certain point in the analysis (pretty much here), we would need more details of the event and jurisdiction, since the law varies by state in the US, though foreseeability is a sine qua non as far as I know.