This is getting interesting.
The damage to the loco is consistent with it nosediving into a pit and the tender taking the cab roof off. The windows in the building on the right are intact which tends to preclude an explosion.
Even enhancing the photo using software I can't tell if the windows are undamaged or just boarded up. Neither can I agree with the damage on the loco being the result of "nosediving" (I'll stay open minded on that).
The high starched white shirt collar on the bystander just in front of the camera suggests pre WW1
My grandfather wore high starched collars all his life well into the 40s and 50s, as did others, so this is inconclusive.
The structure in the background looks, to me, like a gas holder.
I don't know how anyone can tell this. Doesn't look that to me even with enhancement, but again I'll stay open minded.
Next, I have researched a list of all accidents on the North Eastern Railway between 1906 and 1923. There were (according to records) 43 in all. I narrowed it down a bit to built up areas (I think we can agree it is not rural) that could have been covered by a Gateshead crane and that left these:
Accident at Felling. 26th Mar 1907 (collision)
Accident at Sunderland. 31st Jul 1909. (derailment)
Accident at Manors East. 21st Aug 1909. (collision)
Accident at Darlington. 15th Nov 1910. (collision)
Accident at Scotswood Bridge Junction. 6th Oct 1911 (derailment)
Accident at Manors East. 1st Mar 1913. (collision)
Accident at Newcastle Central. 25th Jun 1913. (collision)
Accident at Newcastle Central. 6th Jan 1914. (collision)
Accident at St Bedes Junction. 18th Dec 1915. (collision)
Accident at Manors East. 31st Oct 1919. (collision)
Accident at High Level Bridge, Newcastle. 24th Nov 1919. (collision)
Accident at Newcastle Central. 9th Sep 1921. (collision)
Accident at Hilda Junction, Tyne Dock. 30th Sep 1921. (derailment)
St. Bedes was discounted because I have the accident report on pdf. file. Scotswood bridge junction did not fit the bill because of the surroundings. The only one that came close was Hilda Junction, but that still did not fit the bill. Therefore I am still left with Sunderland during WW2.......or......the interesting and possible scenario by 52A of an accident inside some works and off the railway company lines (really interesting possibility). I'm still going for Sunderland, but I would welcome someone proving me wrong.
Interestingly, it looks like Newcastle and Manors East seemed to have more than their fair share of accidents.
The world is seldom what we wish it to be, but wishes don't change it.