My apple watch series 1 screen just cracked on its own

So last week Friday 21st September 2018, I went to bed, left my watch on the same normal spot I place my accessories. surprisingly woke up got dressed to go out and noticed my apple watch series 1 screen was shattered. this is very strange as there was no physical accident involving the watch.

So my question's are;

1. Do the apple watch screen have a life span?

2. Are some of the apple watch series 1 defective?

3. Am I the only one experiencing this bizarre situation

4. Is there a program like the sleep/wake button on the iPhone 5 that will replace defective apple watch series 1 screen for free if your device falls within a certain batch?