The ship that smashed into the Francis Scott Key Bridge and collapsed the famous Baltimore structure into the river was carrying 56 containers of hazardous materials - but Coast Guard leaders say an inspection thus far shows no signs of a dangerous spill.

The M/V Dali cargo ship was also carrying more than a million gallons of fuel at the time of Tuesday morning's impact, according to the Coast Guard, which said there are no obvious signs of fuel leaks. Officials stressed there is no danger to the public.

The Coast Guard "moved aggressively" to board the vessel and inspect the cargo, said Vice Admiral Peter Gautier in a White House briefing Wednesday. So far the agency has found no evidence that any hazardous materials were released, Gautier said.

Hazmat inspectors have found no evidence that the Dali's hull is leaking any fluids into the river, he said. Efforts are underway to plan how the bridge will be disentangled from the Dali so the ship can be moved.

"The vessel bow is sitting on the bottom because of the weight of that bridge debris on there," he said. "The vessel is stable, but it still has over 1.5 million gallons of fuel oil and lube oil on board."

Is there a threat to a public from the Dali and its cargo?

“There is no threat to the public from the hazardous materials on board,” Gautier said. “We’ve obtained the vessel manifest that container ships carry and done analysis of the types of hazmats that are on board."

A specialized Coast Guard hazmat team on board with air monitoring equipment hasn’t detected anything coming off the containers, he said. "We have not determined that there’s any kind of release (from the cargo) at this time."

"There’s no indication that there’s any flooding or any damage underneath the water line to that vessel," he said. Underwater surveys were underway Wednesday with a remotely operated vehicle and divers to inspect for any potential damage.

The Coast Guard is the lead agency for finding any discharges, for identifying the shipping containers on the vessel and for any clean up effort, said Kelly Offner, a media and public affairs specialist with the U.S. Environmental Protection Agency.

What is known about the Dali's cargo?

Here's what Gautier said:

• 4,700 cargo containers were on board
• Two are missing overboard, but neither contained hazardous materials
• 56 contained hazardous materials.
• 13 or so containers on the bow of the ship were damaged in the collapse.
• The majority of the hazardous materials containers are closer to the pilot house and are completely unaffected by the damage to the bow of the ship.

Most of the hazardous materials in the shipping containers were things like mineral oils, Gautier said. "And even though they're hazardous, we've determined there really isn’t any kind of threat to the public."

Who's overseeing any environmental investigation and cleanup?

Several agencies are on scene and working together, said Offner and Jay Apperson, deputy director of communications for the Maryland Department of the Environment.

The EPA has "a couple of people" on scene, who are technical experts and part of a federal emergency response team, to provide assistance with any shipping containers if needed, Offner said.

Maryland state officials are "conducting water sampling upriver and downriver of the site," in coordination with federal officials, Apperson said.

Cargo manifests are critical

The cargo manifest the Coast Guard used to review the cargo in containers on the Dali is required by federal law.

The rules are particularly meticulous for hazardous materials, said Steven Keats, vice president and partner for Kestrel Liner Agencies, a global logistics agency.

"There's an extremely rigorous vetting of the cargo before it's even accepted for shipping," Keats said. A customer shipping cargo has to submit a materials safety data sheet that details the product, emergency protocols and who gets notified if something happens.

Not every ship can take every class of hazardous material, Keats said, so the shipping owner has to individually approve each cargo container. "That's very rigorous, and it's loaded on to the vessel, in a certain position on the ship, depending what it is."

Mistakes or misstatements can cost companies a lot of money, Keats said. "There's big fines if you violate this stuff, and misdeclarations can get you big civil fines."

What's happening with the salvage of the Dali?

The ship's operator has mobilized its marine salvage plan and its pollution response plan, Gautier said. The contracted salvage company is Resolve Marine Incorporated, and it's mobilizing resources "to take the next steps appropriate to refloat the vessel and remove it from that area."

The critical thing is that a piece of the bridge remains on the bow of the ship, he said. The Coast Guard will coordinate with the Army Corps of Engineers and contractors on removing the debris before the vessel can be moved.