The U.S. Coast Guard ended a second round of investigative hearings into the sinking of the freighter El Faro during which the disaster was characterized by one investigator as "a colossal failure" of management.

Testimony ended Friday after two weeks, during which a National Transportation Safety Board investigator said "few would dispute" that the loss of the El Faro represented a management failure by Tote Services, Inc.

The 790-foot El Faro sank after losing propulsion and getting caught in Hurricane Joaquin in October. All 33 aboard died.

On Thursday, NTSB lead investigator Tom Roth-Roffy asked Tote executive Peter Keller to describe management failures that led to the ship's loss.

Keller said he couldn't and called the sinking "a tragic accident."

On Friday Roth-Roffy backpedaled, apologizing to Tote and saying NTSB had reached no conclusions in its investigation.