Iphone 6s photos turn completely grey on camera roll and when imported to iPhoto

Took some shots today on my iPhone 6s and when I went to review them, a few of them were completely grey.

When I came home to import then into iPhone I could see them as thumbnails but when imported they turn grey again. Opened the photos in Image Capture and the same problem. Even in finder you can see them as thumbnails but when they scale to a larger size they become all grey images. When these images are opened in photoshop I get an error message "jpg file name too short etc." and am unable to open the file in photoshop even when renaming the JPG file extension. I checked the file size of these images and they're a mere 16k vs the normal 1mb+ size of an iPhone photo - which leads me to believe they were not saved properly to the phone after they were taken perhaps...

Is there a way to restore these images or are they completely lost for whatever reason.

Thanks!