It's doubtful that it actually happened that way; don't believe everything you read in books!

I'm glad you asked, since I'm a full-time professional Bible translator who also taught beginning Hebrew for seven years. In the first place, it doesn't say the bears tore them "to pieces," but only mauled them. In the second place, the word "children" was used of Joseph when he was 28 years old, so it's a mistranslation. They weren't children; this was a gang of toughs. In the third place, the text shows that they had surrounded him. How does it show that? Well, there are two separate Hebrew words for "bald." When they said "Go up, thou bald head," they were using the word for someone who is bald in back, and therefore this wasn't just a group of juvenile delinquents who saw him coming and mocked him on the way into their city; they were both in front of and behind him. And in the fourth place, there was the nature of what they said. "Go up." Elijah had already ascended into heaven. They were telling him to do the same thing--to go up, to leave the earth, therefore to die. They were cursing him. You know what happens when you're the lone person (and an unarmed old man at that) in a crowd of 42 juvenile delinquents who are mocking and cursing you and wishing you would die. You are shortly going to be subject to extreme violence and possibly death. So the Lord created a distraction in the form of angry she-bears and the prophet could carry out his mission.

I found this in my Old Testament student manual: “Should Elisha Be Blamed for the Death of These ‘Children’? “In answering this question consider the following interpretations: “1. The word that in the King James Version is translated ‘little children’ means young as compared to old, and can be translated not only as child, but as young man, meaning a servant or one fit to go out to battle. “2. In verse 24 the idea ends. This ending is indicated by a period after ‘and cursed them in the name of the Lord.’ The verse then states that two she bears came out of the woods. The assumption that Elisha directed the bears may not be justified. [Adam] Clarke suggested:    ‘But is it not possible that these forty-two were a set of unlucky young men,     who had been employed in the wood, destroying the whelps of these same     she-bears, who now pursued them, and tore them to pieces, for the injury     they had done? We have already heard of the ferocity of a bear robbed of her     whelps; see at the end of [2 Samuel chap. 17]. The mention of she-bears     gives some colour to the above conjecture; and, probably, at the time when     these young fellows insulted the prophet, the bears might be tracing the     footsteps of the murderers of their young, and thus came upon them in the     midst of their insults, God’s providence ordering these occurrences so as to     make this natural effect appear as a Divine cause. If the conjecture be correct,     the bears were prepared by their loss to execute the curse of the prophet,     and God’s justice guided them to the spot to punish the iniquity that had     been just committed’ (*The Holy Bible… with a Commentary and Critical     Notes*, 2:486).” Certainly a bit of conjecture there, but it makes sense to me!

He was extremely sensitive about his bald head.