Relatives of the man whom authorities suspect of throwing his 3-year-old son from the Key Bridge on Sunday said in a statement that the incident has had a "truly devastating impact" on the families involved.

"The Johnson family has lost one child, and our family has lost two," according to the faxed statement, signed, "The family of Stephen Nelson." Natisha Johnson is the boy's mother.

The Sun confirmed yesterday through a family member of the suspect that the statement came from the Nelsons. It is their first public comment on the case, and they refused requests to be interviewed.

Maryland Transportation Authority Police, which oversees safety on the Key Bridge, is investigating the case as an apparent homicide, and they have said they will charge Nelson, 37, with murder. Police said Nelson attempted suicide and is hospitalized in a drug-induced coma.

Police said they believe Nelson stopped on Key Bridge on Sunday night and tossed his son - Turner Jordan Nelson - into the frigid Patapsco River. He then returned to his mother's home in West Baltimore and drank a mixture of household cleaners, police said.

"Turner was Stephen's world, and he was trying very hard to spend as much time with Turner in the daytime as well as on weekends," the family statement says. "There wasn't a day that has gone by before this tragedy that Stephen didn't speak lovingly of his son."

MdTA police and other agencies have been searching for the boy since Sunday night. The alleged incident was not caught on surveillance cameras that are near the bridge, at the toll plaza, authorities said.

The Baltimore Fire Department used sonar equipment to help with the search yesterday, but reported no new developments yesterday afternoon.

Turner's parents - Nelson and Johnson, 28 - had been together for four years before they broke up in 2004. In the past, they had argued over custody of the boy, which was documented in court filings in Baltimore County.

gus.sentementes@ baltsun.com