How did my dog die?

My dog passed away a few days ago and had to be put down. He was 13 and was a Siberian husky malamute mix. He had nerve pain due to disc and back issues and he couldn’t walk as well because of that. We tried giving him steroid medication to help with the pain and it didn’t work. But his tumor on his leg didn’t spread to his lungs but it burst a few days before he passed. Could we have done anything to prevent his tumor from bursting? The vet said that his back issues were hereditary. He was able to function after we took him home from the vet after we found out he had genetic back issue but his tumor bled. What do you think caused his tumor to burst and bleed a lot? Was it our fault? What do you think he died from?

Updates
3 mo
He couldn’t even move or get up to walk or eat a day before he died. But eventually the tumor stopped bleeding. Only half the tumor bled. You think it definitely was the genetic back issue that caused him to pass away? I still am grieving and upset about all this.
How did my dog die?
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