Below are some reasons Google might delete your blog at any time without your notice.
#1. Adult Contents/Materials: Google is strictly against posting of Adult contents or pornographic materials such as Photos, Videos, Links etc without specifying that your blog is an adult content oriented blog.
If you must post adult contents on your blog, you must specify that your blog is an adult blog from your blogger dashboard settings.
#2. Virus/Malware: Google might delete your blog if malware/virus has been detected on your blog. This is because Google they always ensure that all products on their system are user friendly. You can always check if your blog has been reported for virus HERE
#3. Spamming Google Products: Your Blogger blog might be deleted by google if you continue Posting your blog links on google products for no reason. For example, You dont have a problem and you just post your blog URL on Google owned services like Webmaster help center just for traffic and backlink reason, Google Will definitely Delete your Blog.
#4. Copyright Infringement: This occurs when you copy someone's content without credits or backlinks to the original content owner. If the person reports you to Google, at first, it will lead to your blog being ranked lowly in google search engine. If it persists, Google will have no option than to ban/delete your blog.
#5. Children Safety Abuse: Your blog might be deleted/banned by Google if you abuse the safety of children by posting items that might immorally exploit children such as Child pornography etc.