unidentified dead bird - is it a long tailed tit or Pied Wagtail Why did it die?

unidentified dead bird - is it a long tailed tit or Pied Wagtail Why did it die?

Observation - unidentified dead bird - is it a long tailed tit or Pied Wagtail Why did it die?. Description: Small black and white bird with long tail feathers.

Small black and white bird with long tail feathers.