How does Grendel die in Beowulf?

At night, Beowulf and his men lie in wait for Grendel in Hrothgar's Mead Hall. When Grendel invades the hall, he kills and eats two of Beowulf's men, which gives him a false sense of security. As he reaches for his third vicitm, Beowulf, he is shocked to discover that his claw is being bent backward causing him immense pain. Their battle concludes with Beowulf's ripping Grendel's arm off, fulfilling his promise to Hrothgar to kill the monster with his bare hands. Beowulf nails Grendel's severed arm to the mead hall rafters and, although Grendel runs away, he is later found to have bled to death in his underwater lair.