Normal Collapses & Premature Collapses :

While working with caving system in depillaring district roof falls after some time when supports are withdrawn from the faces, this type of collapses called as "Normal Collapse" In some of cases roof fall occurs while withdrawing of supports or before withdrawn of supports from faces, this is called "Premature Collapse"

Causes or reason for premature collapse is

1. Long area of depillaring.

2. Supports not done in time or not in proper order.

3. Method of de pillaring

4. Geo-mechanical properties of Immediate roof.