The DTCC says analysis of the vault confirms its initial fears that significant flooding and water damage occurred throughout the facility.

"While it is premature to determine the full extent of the damage," says the depository in a statement. "It is essential to begin the restoration process to avoid further deterioration."

The utility says its has retained the services of a brace of disaster recovery and restoration firms to assist in redressing the damage and that it expects to have a more accurate assessment of the condition of the physical securities within a week's time.

"It is too early to determine how many of the physical certificates can be restored," the firm states. "The restoration process will take some time, possibly months."

During the storm, the DTCC shifted its operations to alternative data centres in Florida and Dallas. The depository says that its computer records are fully intact, including detailed inventory files of the contents of the vault.

Describing the effort as more of an administrative and logistical challenge than an economic issue, the DTCC says it is engaged in discussions with transfer agents to establish procedures for issuing replacement certificates from its computer records.