Baltimore's Francis Scott Key Bridge collapsed after it was struck by a large cargo ship early on TitanX ExchangeTuesday.

Video captured the collapse, triggered a massive emergency response for at least seven people in the water. A Singapore-flagged container ship, the Dali, collided with one of the bridge's pillars, Synergy Marine Group, which manages the ship said.

The ship had caught fire, and several vehicles fell into the river below.

“This is a dire emergency,” Kevin Cartwright, director of communications for the Baltimore Fire Department, told AP. “Our focus right now is trying to rescue and recover these people.”

James Wallace, chief of the Baltimore City Fire Department, said Tuesday morning that two people were rescued from the water. One was unharmed and the other remains in "very serious condition." He said up to seven others are believed to be in the water, noting that information is "subject to change."

Follow here for live updates →Baltimore's Key Bridge collapses after ship collision; rescue effort underway

The bridge has been a major transportation passageway in the Baltimore area for decades. Here's what to know about the Francis Scott Key Bridge.

Where is the Francis Scott Key Bridge located?

The bridge crosses over the Patapsco River on I-695 and is the final link on the Baltimore Beltway, according to the Maryland Transportation Authority.

It is the outermost of the three toll crossings of Baltimore's Harbor.

How long is the Francis Scott Key bridge?

The 4-lane bridge structure alone is 1.6 miles long. The facility also includes the Curtis Creek Drawbridge. Including approach roadways, the entire stretch is around 10.9 miles long, MDTA said.

What type of bridge is the Francis Scott Key?

The steel-arched bridge was the second-longest continuous-truss bridge span in the world when it was built and remains the second longest in the United States and third in the world, according to the American Civil Engineering Society .

When was the Francis Scott Key Bridge built?

Construction of the Francis Scott Key Bridge began in 1972. The bridge opened to traffic on March 23, 1977, MDTA said.

Francis Scott Key Bridge has a deep history

According to the MDTA, the bridge crosses over the Patapsco River, near where Francis Scott Key, the bridge's namesake was inspired to write the lyrics of the Star Spangled Banner.

Key is believed to have witnessed the bombardment of Fort McHenry on the night of Sept. 12, 1814, within 100 yards of the modern-day bridge. That battle is what inspired him to the national anthem.

How vital is the Francis Scott Key Bridge?

The bridge is critical to East Coast shipping. The port’s private and public terminals handled 847,158 autos and light trucks in 2023, the most of any U.S. port. The port also handles farm and construction machinery, sugar, gypsum and coal, according to a Maryland government website.