Crews have opened a second temporary channel allowing limited marine traffic to bypass the wreckage of Baltimore's collapsed Francis Scott Key Bridge, which is blocking the vital port's main shipping channel. Authorities said Tuesday that work is also continuing to open a third channel that will allow larger vessels to pass through the bottleneck since the bridge collapse one week ago. The channels are primarily for vessels helping with the cleanup effort. Meanwhile, Gov. Wes Moore said at a news conference that rough weather conditions in recent days have made it unsafe for divers who are trying to recover the bodies of the four construction workers believed trapped underwater in the wreckage.

Maryland Gov. Wes Moore has been granted $60 million in immediate federal aid but warns of a "very long road ahead" after the Baltimore bridge collapse. Moore says "the best minds in the world" are working on plans to clear the debris and move the cargo ship that struck the Francis Scott Key Bridge. Massive barges carrying cranes are heading to Baltimore to begin the challenging work of removing twisted metal and concrete from the blocked shipping channel. Officials say they'll need to clear the wreckage before resuming the search for four workers who are still missing.

An unusually warm winter has left the Great Lakes all but devoid of ice and sent scientists scrambling to understand the possible consequences as climate change accelerates. Researchers believe that warmer lakes could lead to bigger algae blooms, more evaporation, and beach erosion, and less oxygen for bottom-dwelling organisms that bigger fish consume. But they don't know for sure because the lakes have been studied relatively little during the coldest months. According to the Great Lakes Ice Tracker website, ice coverage on the lakes dropped to just 3% in mid-February, a time when usually 40% of the lakes are covered. That's the lowest figure since at least 1973, when the site's records begin.

The U.S. government is trying to stop a planned expedition to the sunken Titanic shipwreck that could recover items of historic interest. The expedition is being organized by RMS Titanic Inc. The Georgia-based firm owns the salvage rights to the wreck and exhibits recovered artifacts. The government's legal challenge to the expedition has nothing to do with the fatal implosion of the Titan submersible in June. It hinges instead on a federal law and a pact with Great Britain to treat the wreck as a memorial to those who died and to prevent entry into its hull.

The deadly implosion of the Titan submersible raises questions about whether the vessel exploring the Titanic wreckage was destined for its own disaster because of its unconventional design and its creator's refusal to submit to safety checks that are standard in the industry. The Titan, developed and operated by OceanGate Expeditions, was touted for a design that included a carbon fiber hull, an elongated cabin for crew and passengers, and more. But outside experts say the design and construction of the submersible put greater stress on its structure, and others say OceanGate's failure to submit to outside safety testing posed additional concerns.

Officials are assessing tornado damage Monday after the storm moved through the City of Virginia Beach Sunday, damaging dozens of homes, downing trees and causing gas leaks. The National Weather Service confirmed Monday that the tornado that touched down Sunday evening was an EF-3, with wind estimates of 140 to 150 mph. No injuries were reported, but Director of Emergency Management David Topczynski says officials assessed 115 damaged structures and that number will likely grow. Severe weather has damaged communities around the U.S. over the weekend. A tornado was also confirmed in Florida and there's historic flooding on the Mississippi River. In Maine, some 50,000 homes and businesses were without power Monday morning after a windy rainstorm.