KENNER, La. (AP) — Wednesday’s hearing into the cause of the Deepwater Horizon oil rig disaster has been canceled because all four scheduled witnesses have declined to appear, a Coast Guard spokesman said.

David Adler, lawyer for Transocean Ltd. subsea superintendent Bill Stringfellow and Transocean subsea supervisor Mark Hay, said he needs more time to prepare because the Coast Guard hasn’t given him copies of investigatory documents.

Transocean subsea supervisors Ray Odenwald and Jim McWhorter apparently aren’t testifying because their lawyer may have a conflict of interest because he represents a Transocean employee who has been named a “party in interest” in the investigation.

The hearing is scheduled to resume Thursday.