Investigation would focus on snow and ice treatment procedures.
The weather also threatened to affect the nation's COVID-19 vaccination effort.
A large water main break in Philadelphia left cars submerged and the area completely flooded.
All 33 passengers and one crew member died in the bunkroom below deck.
Searches for missing people were underway and will increase during the day.
Efforts to stay warm and dry while camping led to at least two fires.
Buildings housing the camp's store and arts and crafts, woodshop and cooking programs were destroyed.
MCI alert for pileup on interstate in Fort Worth.
Battalion Chief Douglas Hatcher said firefighters saved most of the building.
Duluth Fire Department got a call from a resident who saw ice shanties floating away.