Ash is a much harder wood, never seen one go like these. They're Salix Fragilis, common name 'crack willow' planted as a cricket bat crop on a 16 year rotation, they get top heavy because the side growth is stripped off annually so grain stays straight for the bats, they were planted far too close to our house originally, the ones at the back overhang the roof bigtime. If they get a few dead leaves stuck in a sharp fork they start rotting at the crook, and eventually split down the middle, the field at the back has 1200, of which around 50 have split, we've seen 8 or 9 go while we've been in the garden, you can actually hear them starting to go about 30 seconds before the big crack.
The owners had a team come down and started work felling them on Friday, 26 are coming down next week. We've been on at them since November, we got the council tree officer involved 2 months back when one came down blocking the drive, very nearly took our chicken house out, he recomended felling the 26 then on safety grounds, but he couldn't enforse it since it's on private land - at least there's no question of liability