Level

Description

Operational

Very light damage, no permanent drift, structure retains original strength and stiffness; all systems are normal

Immediate Occupancy (IO)

Light damage, no permanent drift, structure retains original strength and stiffness, elevator can be restarted, Fire protection operable

Life Safety (LS)

Moderate damage, some permanent drift, some residual strength and stiffness left in all stories, damage to partition, building may be beyond economical repair

Collapse Prevention (CP)

Severe damage, large displacement, little residual stiffness and strength but loading bearing column and wall function, building is near collapse