Freeing the Ever Given was the easy part. Now, the investigation.

Experts boarded the massive container ship Tuesday that had blocked Egypt’s vital Suez Canal and disrupted global trade for nearly a week, seeking answers to a single question that could have billions of dollars in legal repercussions: What went wrong?

As convoys of ships again began traveling once more through the artery linking the Mediterranean and Red Seas, a canal service provider said more than 300 vessels carrying everything from crude oil to cattle were still waiting for their turn in a backlog-clearing process that will take days. Egyptian government officials, insurers, shippers, and others similarly waited for more details about what caused the skyscraper-sized Ever Given to become wedged across the canal on March 23.

When blame gets assigned, it will likely lead to years of litigation to recoup the costs of repairing the ship, fixing the canal, and reimbursing those who saw their cargo shipments disrupted. Since the vessel is owned by a Japanese firm, operated by a Taiwanese shipper, flagged in Panama, and now stuck in Egypt, matters quickly become an international morass.

“This ship is a multinational conglomeration,” said Capt. John Konrad, the founder and CEO of the shipping news website gcaptain.com.

Experts boarded the Ever Given as it idled Tuesday in Egypt’s Great Bitter Lake, just north of the site where it previously blocked the canal. A senior canal pilot, speaking on condition of anonymity because he was not authorized to talk to journalists, told The Associated Press that experts were looking for signs of damage and trying to determine why the vessel ran aground.

There could be significant damage to the the ship, Mr. Konrad warned. Stuck for days across the canal, the ship’s middle rose and fell with the tide, bending up and down under the tremendous weight of some 20,000 containers across its quarter-mile length. On Monday, when workers partially floated the ship, all that pressure came forward to its bow.

“Structural integrity is No. 1. You know, there was a lot of strain on that ship as it was sagging in the waterway,” Mr. Konrad said. “They have to check everything for cracks and particularly that rudder and the propeller in the back that’s connected to the engine room.”

“And then they have to go through all the mechanical equipment, make sure they test the engines, all the safety valves, all the equipment, and then determine that it’s safe to sail either by itself or with a tug escort to the next port,” he added.

The ship’s owner, Shoei Kisen Kaisha Ltd., said Tuesday that it would be part of the investigation along with other parties, though it did not identify them by name. It also refused to discuss possible causes of the grounding, including the ship’s speed and the high winds that buffeted it during a sandstorm, saying it could not comment on an ongoing investigation. Initial reports also suggested a “blackout” struck the vessel, something denied by the ship’s technical manager.

The company added that any damage to the ship was believed to be mostly on its keel. It said it was not immediately known whether the vessel will be repaired on site in Egypt or elsewhere, or whether it will eventually head to its initial destination of Rotterdam. That is a decision to be made by its operator, rather than the shipowner, the company said.

The Ever Given was seen to be stationary in the canal lake from the town of Fayed on Tuesday, still stacked with containers, with a specialist tugboat nearby. Other vessels in transit navigated around it.

The grounding of the ship had halted billions of dollars a day in maritime commerce. Analysts expect it could take at least another 10 days to clear the backlog – though Egypt’s president said Tuesday it would take just three. The losses to shippers, as well as any physical damage to the vessel itself, likely will see lawsuits.

Shoei Kisen Kaisha Ltd. is covered with some $3 billion in liability insurance through 13 Protection & Indemnity Clubs. Those clubs are not-for-profit mutual insurers used by the vast majority of global shipping firms.

Global legal firm Clyde and Co. said the Ever Given’s owner likely would pay Egypt’s canal authority for the assistance already rendered to the vessel. The authority also could fine the Ever Given.

“We anticipate a detailed investigation will follow which will determine the cause,” the firm said. ”Evidently the cause will impact upon the legal liabilities of the ship and cargo interests.”

Egyptian President Abdel Fattah al-Sisi traveled Tuesday to the canal-side city of Ismailia to praise those who freed the vessel.

Speaking to a small group of reporters on a dock overlooking the waterway, Mr. al-Sisi deflected questions about the investigation, saying Egypt would not interfere in a probe that will be left to “the specialists.”

“We want to confirm to all the world, that things are back to as they were,” he added. He stood before a sign that said: “Welcome to the Suez Canal: Egypt’s lifeline of peace, prosperity, and development.”

On Monday, a flotilla of tugboats helped by the tides wrenched the bulbous bow of Ever Given from the canal’s sandy bank, where it had been firmly lodged. The tugs blared their horns in jubilation as they guided the Ever Given through the water after days of futility that had captivated the world, drawing scrutiny and social media ridicule.

The Ever Given had crashed into a bank of a single-lane stretch of the canal about 3.7 miles north of the southern entrance, near the city of Suez. That forced some ships to take the long, alternate route around the Cape of Good Hope at Africa’s southern tip – a 3,100-mile detour that costs ships hundreds of thousands of dollars in fuel and other costs.

The unprecedented shutdown of the canal while the Ever Given remained stuck, which raised fears of extended delays, goods shortages, and rising costs for consumers, added to strain on the shipping industry already under pressure from the coronavirus pandemic.

This story was reported by The Associated Press. Jon Gambrell reported from Dubai, United Arab Emirates. AP writers Mari Yamaguchi in Tokyo and Isabel DeBre in Dubai contributed to this report.