Search halted in water taxi accident
Investigators looking into safety procedures
Water taxi capsizes in Baltimore harbor.
Passengers were thrown from the boat into chilly waters.
The rescue operation has turned to a recovery mission.
BALTIMORE, Maryland (CNN) -- Divers halted their search Sunday evening for three people presumed dead in a water taxi accident in the Baltimore harbor, said National Transportation Safety Board Chairman Ellen Engleman Conners.
Search efforts will be resumed Monday morning, she said.
The recovery teams were looking for a man and a woman, both 26, and a 6-year-old boy missing a day after a squall capsized the 36-foot pontoon boat.
The boat was carrying 25 people. Twenty-two people were rescued, but one of those -- a 60-year-old woman -- later died.
Baltimore Fire Chief William Goodwin said seven people were still hospitalized Sunday, two of them -- an 8-year-old girl and a 30-year-old woman -- in critical condition.
Officials refused to release information about the victims of the accident until all families had been notified.
"At least 18 of the 25 [on the boat] were not from the Baltimore area," police Maj. Frederick Bealfield said.
The vessel was righted Sunday afternoon and towed to a dock, where it will be lifted from the water for an inspection of its hull, steering and propulsion systems, Conners said. A preliminary inspection of the steering indicated it was normal, she said.
NTSB investigators said everyone they interviewed Sunday, including the boat's captain and first mate, is cooperating. The boat's captain voluntarily gave investigators blood and urine samples, which will be used for standard toxicology studies, Conners said.
Two passengers and officials of the companies that owned and operated the boat were also interviewed, Conners said.
The NTSB is particularly interested in what the passengers may have been told about life jacket use, she said. The boat was required to carry one life jacket per person aboard, but their use was not required.
The 36-foot Seaport Taxi pontoon boat was certified to give 30-minute tours between several points of interest and was on one of its regular loops around the harbor when the accident occurred.
"It would be required to have either a lengthy safety education briefing at the beginning or a combination summary verbal education at the beginning and placards about [the life jackets'] use," Conners said.
"We'll also be looking at the policies, procedures, training for the crew, and the actual implementation of the policies," she said.
The boat's condition and maintenance record, and the operator's safety record, would also come under scrutiny, Conners said. Five other vessels operated by Seaport Taxi will also be inspected, she added.
Goodwin said the water taxis on Baltimore Harbor have an excellent safety record, ferrying about 70,000 people per year for at least a decade with no accidents until this one.
Goodwin said the storm that blew over the harbor Saturday afternoon was freakish.
"It seems to be somewhat of an anomaly that happened yesterday that no one took notice of until after the accident," he said. "There was a brief warning and then some sort of cell passed over the harbor from the northwest, winds 50 miles per hour, and then it passed over. As quick as it came it was over."
CNN's Kathleen Koch contributed to this report.