My father recently passed. I had services and burial on separate days. When burial time came (per-arranged with cemetery) and my family and I showed, nothing had been done. The site had not been excavated at all. They basically made us wait for several hours while the process was carried out. The alernative - perform final resting rituals at the curb with nothing but the casket. Do I have cause to sue for neglect and/or emotional distress as this was heartbreaking?

I think you have a valid cause of action, but I doubt if you will recover very much. Determining a monetary value for what you suffered is going to be difficult.

But I would consult with a personal injury attorney, most offer a free consult, and see what they think.

For a filing fee of around $50, you could sue in Small Claims by yourself. Document the delay as best you can with testimony, video, anything you can. Find out the limit in your state, because it can vary from about $5,000 to 10,000. You can sue for that much pain and suffering (and any actual costs?) even if you aren't awarded that much. (There's a chance you won't get anything, but I think you will, depending on how well you present your case.) I hope you have written proof of the arrangements, and that any requirement that payment be made in advance was done. Read the contract carefully first.

Find out the limit in your state, because it can vary from about $5,000 to 10,000. You can sue for that much pain and suffering (and any actual costs?) even if you aren't awarded that much.

Most small claims courts restrict suits to actual damages and do not allow pain and suffering. The only actual damages I see here are the time lost waiting for the excavation to be completed. That is probably minimal.

Do you have a written contract that specifies the date and time of the burial? If so, read it to be sure there's no small print that lets them off the hook for not being ready.

... Do I have cause to sue for neglect and/or emotional distress as this was heartbreaking?

Losing your father may have been heartbreaking, but losing a couple of hours of time would be merely an inconvenience.