Maps and video show site of bridge collapse in Baltimore

A major search and rescue operation has now transitioned to a recovery mission at the site of the Francis Scott Key Bridge in Baltimore after it was struck by a cargo ship and collapsed early Tuesday , sending vehicles and people plunging into the water below. The U.S. Coast Guard said the ship had reported losing propulsion and control as it was leaving Baltimore harbor, before the collision occurred at around 1:30 a.m. ET.

Two survivors were pulled from the water soon after the collapse, officials said — one unhurt and one with serious injuries, who was treated at a hospital and later released, CBS Baltimore reported .

Six were missing and presumed dead. Officials said the bodies of two victims were recovered Wednesday.

Maryland Department of Transportation Secretary Paul Wiedefeld said all six were construction workers who were filling potholes on the bridge at the time.

Maryland Gov. Wes Moore declared a state of emergency, with city, state and federal teams converging at the scene.

Map of the Key Bridge in Baltimore

The Key Bridge crosses the Patapsco River, a key waterway that along with the Port of Baltimore serves as a hub for East Coast shipping. CBS News Baltimore  reports that the four-lane, 1.6-mile span was used by some 31,000 people a day.

The Maryland Transportation Authority said all lanes were closed in both directions on I-695, which crosses the Key Bridge. The agency said traffic was being detoured to I-95 and I-895.

The portion of the bridge that collapsed was on a stretch connecting Hawkins Point, on the south side of the waterway, and Dundalk, on the north.

Video of the Key Bridge collapse in Baltimore

Video captured the moment the heavily loaded container ship struck a bridge support, sending sections of the overpass tumbling into the river below.

Officials said in a news conference that the ship had reported losing power and a mayday had been issued before the collision, which allowed officials to stop traffic onto the bridge. Officials did not clarify how many vehicles were on the bridge at the time of the collapse.

Moore said he "can confirm that the crew notified authorities of a power issue," and he said that the decision to stop traffic onto the bridge "saved lives last night."

Earlier Tuesday morning, Baltimore Mayor Brandon Scott called the collapse "an unthinkable tragedy."

"We have to first and foremost pray for all of those who are impacted, those families, pray for our first responders and thank them," he said. "We have to be thinking about the families and people impacted. We have to try to find them safe."

What was the ship's route?

The Singapore-flagged Dali, operated by charter vessel company Synergy Group, was chartered by and carrying cargo for Maersk. It had left the Port of Baltimore, just north and west of the bridge, before turning to head south and east along the Patapsco River.

The ship had been in the port for two days, according to ship tracking website VesselFinder , and was expected to spend nearly a month at sea before it reached Colombo, Sri Lanka.

CBS News analyzed the path of every cargo ship taking this route over the past month and found Dali had veered more than 100 yards off the usual route when it struck the bridge support.

Timeline of the disaster

Click the arrow below to see an interactive timeline of how the collision occurred.

Before-and-after photos of the Francis Scott Key Bridge

Baltimore's Francis Scott Key Bridge opened to traffic on March 23, 1977, and was a crucial thoroughfare for the region, carrying some 11.3 million vehicles per year.

The photos below show how it looked following the collapse Tuesday morning, and how it looked intact just a few days earlier.

A witness who lives near the bridge told CBS Baltimore the collapse felt like an earthquake and sounded like "a big bash of thunder."

"The whole house vibrated, like my house was falling down," he said. "I've been in this neighborhood 57 years, I remembered when they built this bridge. Can't believe it's gone."

Another resident reflected on being on the bridge just yesterday. "To see the bridge gone knowing I was on that bridge not even 10 hours ago — it's devastating."