You may have a good case. The outcome will depend on many factors, some of which you may not have thought about. Many attorneys will offer a free consultation, I would suggest that you contact one a set up an appointment.
I'm very sorry to hear about your father's passing which I'm sure has been very difficult for you to deal with. Without having much more information, it's difficult to determine whether you may have a valid claim. I would recommend you obtain as many records as you can from the hospital and consult an attorney who specializes in medical malpractice matters. Generally, they have resources they can use to evaluate the records to determine whether the hospital acted appropriately when your father came in.
A roundup of the best tips and legal advice.