While it's not common for glass shower doors to suddenly shatter, it is possible. Shattering can occur due to a variety of reasons, including:

Defects in the Glass: Poorly manufactured glass or glass with inherent defects can be prone to sudden breakage.

Installation Issues: Incorrect installation, such as not leaving enough space for the glass to expand and contract, can lead to stress on the glass and potential breakage.

Damage: Any existing damage, such as chips or cracks, can compromise the structural integrity of the glass, making it more prone to shattering.

Temperature Fluctuations: Extreme temperature changes, such as hot water from a shower followed by cold air, can create stress on the glass and lead to breakage.

Impact: A significant impact or force applied to the glass, whether intentional or accidental, can cause it to shatter.

To reduce the risk of a glass shower door shattering, it's important to:

Ensure proper installation by a qualified professional.

Regularly inspect the glass for any signs of damage.

Avoid slamming the door or applying excessive force.

Be cautious with temperature changes, such as avoiding extremely hot water followed by cold air.

If you notice any damage or defects, it's best to address them promptly to minimize the risk of unexpected breakage. Additionally, tempered glass is often used for shower doors because it is more resistant to shattering than regular glass. If you have concerns about your shower door, it's advisable to consult with a professional for an assessment.