(NewsNation) — Search and rescue efforts related to the Titan submersible that tragically imploded with five people onboard cost the U.S. government an estimated $1.6 million, according to a defense budget expert.

That estimate takes into account costs for fuel, maintenance, personnel and other operating expenses for the various U.S. assets involved, said Mark Cancian, the senior adviser with the Center for Strategic and International Studies (CSIS) who conducted the analysis.

The calculation does not include any salvage costs to recover wreckage from the submersible, which could get “quite expensive,” Cancian pointed out.

Titan went missing on June 18 after it lost communication less than two hours into its dive to the Titanic shipwreck, triggering an international search that included aircraft, surface ships and remote operated vehicles.

The massive effort led many people to question who would be footing the bill for the operation.

By the time the sub was located on June 22, it was already too late. Officials determined that Titan had suffered a “catastrophic implosion,” killing all five passengers aboard.

In the end, Cancian said the financial cost was “fairly modest” and pointed out that other search and rescue operations have been far more expensive.

He also pushed back against those who mocked the passengers’ wealth.

“The fact that these were billionaires is irrelevant,” he said. “Whether you are poor or rich, the U.S. government has committed to going and rescuing you if it can, and I think that’s the right policy.”

The $1.6 million estimate only applies to the U.S. government’s portion of the operation. Canada also deployed significant assets to the search area and Cancian believes it spent about the same.

But the exact costs, and who ultimately pays them, are still unknown.

Cancian noted that any costs incurred by the federal government would be moved from other areas of the budget, rather than added later.

“The Coast Guard and [Department of Defense] are not going to receive $1.6 million extra in their budgets,” he said.

An investigation into the incident is still ongoing.

A U.S. Navy official previously said a large salvage system would not be used to retrieve Titan because there were not enough large pieces left. But other salvage operations from the ocean floor were ongoing as of late June.

OceanGate, the company behind the submersible, won’t be responsible for reimbursing the government for rescue efforts, Paul Zukunft, former head of the Coast Guard, recently told the Washington Post.

“It’s no different,” he told the Post, “than if a private citizen goes out, and his boat sinks. We go out and recover him. We don’t stick them with the bill after the fact.”

On Thursday, OceanGate announced it had suspended operations.

Among those who died in the accident were OceanGate CEO and pilot Stockton Rush; two members of a prominent Pakistani family, Shahzada Dawood and his son Suleman Dawood; British adventurer Hamish Harding and Titanic expert Paul-Henri Nargeolet.