GS450hATL

4/11/2016.....My 07 GS450h's check engine light popped on and temp gauge suddenly showed it overheating then before I could pull over the engine made a loud screeching noice with white smoke coming from the exhaust and a lil from under the hood. Then the car immediately turned itself off.....Almost like in a self preservation mode to prevent further damage and won't engage once l pushed to restart the engine. Probably for the best in hindsight but once l opened the hood noticed coolant reservoir was EMPTY which was surprising as I'd just had an synthetic oil change at Firestone 9 days prior and their invoice receipt claimed my coolant was full and checked as OK. Had car towed to Hennessey Lexus in Duluth and awaiting what they discover. Also found out a fuel system line recall is on my car which needs to be fixed (free of charge thank God) to boot. Scared senseless about a potentially enormous hybrid battery replacement bill and hoping one of you guys out their had a similar experience and could give some helpful advice or share your wisdom in this matter.