We can't access your photos.
If the device was stolen, and the photos weren't backed up, then they are gone. The same goes for if the phone died and you didn't have the files backed up somewhere, they are gone.
If they were uploaded to google then you can get them back. Instructions included below.
If they were on your phone and you accidentally deleted them, info on trying to get those back is included below as well.
To get photos back from google...
1. Open the "Google Photos" app.
2. Tap the photo you want to save to your phone.
3. Now tap the "Options" menu.
4. And finally tap "Restore".
5. Repeat for each image.
Or, to get them all at once...
1. Log into the google account associated with the app.
2. Download all the images to an empty folder on your computer.
3. Connect the phone to the computer via USB cord.
4. Copy the images over to the phone or sd card.
In regards to deleted files... While there is no guaranty that you can get them back. Deleted does mean deleted. There are a few apps/programs out there that 'may' be able to help you recover the data.
A few of the programs you could try would be... DiskDigger, MobiSaver, Android-Recovery and Tenorshare. They are all data recovery apps/programs. There are many others out there, so check around and see which you would rather try. There is also one called RECUVA, that I have heard is free, which you could try.
One important note though, most of these programs are not free. They may say they are "free" or have "Free Trials" and "Free Downloads". Yet to actually recover your data, and get your files back, you may be have to purchase the program/app. Just so you know.
NOTE: For future reference, I really would suggest backing up your data to a computer or cloud. Often. Better to spend the time doing that, rather than to be out all that stuff if the phone dies, things get deleted/erased or it gets stolen.