[details=“English Translation”]The driver of the car died on the spot after the accident.
[/details]
Taken at face value, “quedó en el sitio”, doesn’t sound that grim, as if the driver stayed at the scene of the accident, maybe until the car got towed away.
The RAE doesn’t have “quedar en el sitio”, but it does have “quedarse en el sitio”.
quedarse alguien en el sitio
loc. verb. Morir en el acto.
Would “se quedó en el lugar” have the same fatal meaning?
I don’t think so, it might be understood because both phrases are similar but quedarse en el sitio is fixed expression and quedarse en el lugar is not.