Thestrals and Hagrid

[megalynn44]

No: HPFGUIDX 69507

Oh so many questions reguarding the Thestrals have been raised. Why 
keep so many if all they do is pull some carriages a couple times of 
year. Why didn't Harry see them at the end of GOF? (well I am 
standing by JKR's explanation on that one) Who is the thin little 
Slytherin boy who could see them? Possibly, finally a GOOD 
Slytherin...

Anyways, one more occured to me last night, and it may be so simple 
that we have already been told, but on my re-reading of the Thestral 
lesson, Hagrid could see them too.  Who has Hagrid seen die? 

I know his father died but am I forgetting the passage that said 
Hagrid was there when his father died? I thought he was away at 
school. And while we are on that subject, how did Hagrid's dad die? 
Or did something else (if so, what?) happen to allow Hagrid to see 
them?

~Megalynn
    Who needs to go skim through COS and GOF for relevent passages 
after thinking while typing and asking more than planned on.