1997 Toyota Avalon Colant tank totally empty and dry

Hi,

My coolant tank is totally empty and dry. I think I have coolant left in my radiator and I have never seen my engine getting too hot.

Do you think its possible for coolant tank to be dry and flushing and refiling the coolant should be all I need to do? Or it can happen only when I have a leak somewhere. I have never noticed anything dripping from my car as such.

Any advice in this regard will be highly appreciated.

Thanks