Here's what we know about the Singapore-flagged container ship that hit the Baltimore bridge

Six construction workers were presumed dead on Wednesday after a massive cargo ship struck the Francis Scott Key Bridge in Baltimore, causing it to partially collapse into the Patapsco River.

The incident, which has wreaked havoc at one of the country's busiest ports and sparked fears about supply chain disruption, has raised questions about the Singapore-flagged container ship involved.

Known as the Dali, the nearly 1,000-foot-long vessel was heading out of Baltimore Harbor and bound for Sri Lanka, when it hit a support pylon of the bridge at around 1:30 a.m. ET.

It appeared to be traveling at roughly 8 knots (about 9 mph) before the collision, according to LSEG shipping data. Video footage of the disaster appears to show the 1.6-mile structure crumpling into the icy water almost immediately after it was struck.

A search and rescue effort was suspended Tuesday evening.

Maryland Gov. Wes Moore on Tuesday said the crew of the Dali was able to send a critical emergency alert that enabled authorities to clear the bridge of further car traffic ahead of impact.

"Between the mayday and the collapse that we … that we had officials that were able to … to begin to stop the flow of traffic, so more cars would not end up on the bridge, which saved lives in a very, very heroic way," Moore said at a news conference.

Moore said the ship's crew notified authorities of power issues prior to the collision and that a preliminary investigation pointed to an accident.

The Dali was previously involved in a minor incident in Belgium's Port of Antwerp, the second-largest port in Europe.

The ship suffered "sufficient damages" in July 2016 when it struck the stone wall of the quay during unmooring maneuvers, according to shipping trafficking website