The operation has moved from a search and rescue mission to a search and recovery effort, according to officials.
ADVERTISEMENTAll six workers missing after a Baltimore bridge collapsed on Tuesday are presumed dead, and the search for them postponed until Wednesday morning.
According to the authorities, the operation has shifted from search and rescue to search and recovery.
On Tuesday, a 300-metre-long container ship struck one of the Francis Scott Key Bridge supports, causing the span to break and fall into the water within seconds.
Two people were retrieved alive from the waters under the bridge, one in serious condition.
The six people unaccounted for were part of a construction crew repairing potholes on the bridge. Police had stopped traffic on the bridge just before the crash and said there is no evidence that anyone went into the water other than the workers.
The collapse is likely to result in a logistical nightmare for the region, potentially lasting months or even years, by halting ship traffic at the Port of Baltimore, a major shipping hub. Additionally, the incident is expected to disrupt both cargo and commuter traffic.
Officials say it is too soon to estimate how long it will take to clear the 15 metres deep channel.