You may have experienced some issues with Safari while using your Mac or iPhone on Wednesday morning. Many OS X and iOS users reported a bug that was causing the browser to crash when using the search bar.
Fortunately, users have reported that turning off Safari Suggestions has provided a fix for the issue. This can be done in iOS by tapping Settings > Safari and then toggling the feature off.
In OS X, the setting is found under Safari > Preferences > Search. Browsing in private mode also does the trick, according to many users.
UPDATE: Apple appears to have fixed the issue.