TAMPA, Fla. (WFLA) — The National Transportation Safety Board detailed during a Wednesday night news conference what is believed to have happened in the moments before a cargo ship crashed into Baltimore’s Francis Scott Key Bridge, sending the bridge collapsing into the water.

The NTSB received six hours of voyage data recorder (VDR) data spanning from midnight to 6 a.m. on the day of the crash. The VDR shows a basic snapshot of what’s happening, including the ship’s speed, heading, RPMs and audio from the crew.

VDRs are required to record 30 days of history, according to the NTSB. Six hours of data were released to investigators immediately, and the rest of it will be obtained later.

Officials with the NTSB boarded the ship to recover information from its electronics and paperwork and to do interviews with the captain and other crew members, NTSB Chair Jennifer Homendy said during a news conference. Twenty-three people, including two pilots, were on the ship when it crashed, she said.

The ship was also carrying 56 containers of hazardous materials including corrosives, flammables and lithium ion batteries, Homendy said. She added that some containers were breached and that a sheen on the water from those materials would be handled by authorities.

The NTSB released the following timeline of events, which are preliminary and could change as the investigation progresses (all times are ET):

• 12:39 a.m.: Ship departed from the Seagirt Marine Terminal
• 1:07 a.m.: Ship entered  the Fort McHenry Channel
• 1:24 a.m.: Ship traveling at a heading of 141 at about 9.2 mph
• 1:24:59 a.m.: Censor data stopped recording, but audio recording continued
• 1:26:02 a.m.: Censor data recording resumed
• 1:26:39 a.m.: Pilot made a radio call for tugs to assist
• 1:27:04 a.m.: Pilot ordered an anchor drop
• 1:27:25 a.m.: Pilot radioed that all power was lost and asked for bridge to be closed
• 1:29 a.m.: Ship was traveling less than 8 mph
• 1:29:33 a.m.: VDR recorded sounds consistent with crash, and dash cameras show bridge lights go out
• 1:29:39 a.m.: Pilot reports to Coast Guard that the bridge is down

Homendy added that the bridge was in satisfactory condition, and its last fracture critical inspection was in May 2023. A fracture critical bridge has no redundancy, and if part of the structure fails, the whole thing fails, she said.

The bridge was built in the late 1970s. Modern bridges are built with redundancy, Homendy said.

The sudden loss of a highway that carries 30,000 vehicles a day, and the disruption of a vital shipping port, will affect not only thousands of dockworkers and commuters but also U.S. consumers who are likely to feel the impact of shipping delays.

The Port of Baltimore is a busy entry point along the East Coast for new vehicles made in Germany, Mexico, Japan and the United Kingdom, along with coal and farm equipment.

Ship traffic entering and leaving the port has been suspended indefinitely. Windward Maritime, a maritime risk-management company, said its data shows a large increase in ships that are waiting for a port to go to, with some anchored outside Baltimore or nearby Annapolis.

Speaking at a White House news conference, Transportation Secretary Pete Buttigieg said the Biden administration was focused on reopening the port and rebuilding the bridge, which was completed in 1977, but he avoided putting a timeline on those efforts. He noted that the original bridge took five years to complete.

Homendy said the NTSB investigation could take 12 to 24 months but that the NTSB may issue urgent safety recommendations during that time. A preliminary report should come in two to four weeks.

“It’s a massive undertaking for an investigation,” Homendy said. “It’s a very tragic event.”

From 1960 to 2015, there were 35 major bridge collapses worldwide due to ship or barge collisions, according to the World Association for Waterborne Transport Infrastructure.

The Associated Press contributed to this report.