Justin Janolis, 10, and his 5-year-old brother, Jonathan, were pronounced dead shortly after being pulled from the water.
Vance County rescuers got the call around noon. Sheriff Thomas Breedlove says the children were apparently playing on a dock before the accident.
"It appeared that the children were riding the bike down the dock and sliding to a stop right at the end of it. Maybe one of them possibly ran over [the end of the dock], went into the water, and possibly the other tried to retrieve him and got in trouble with him," Breedlove says.
Breedlove says the children lived a short bike ride from the lake. He says the boys' father hurried to the lake after learning the kids went there. The father scrambled to get neighbors involved in the search, and a 16-year-old pulled the first child from the water.
The sheriff believes the brothers drowned at least 30 minutes prior to the call coming in.
Skid marks found on the dock may have been left by the boys as they rode their bikes, deputies say.
Kerr Lake State Parkis popular for boating and fishing, but swimming is not advised. Three people drowned there during the summer in 1998, and a Rocky Mount man drowned in Kerr Lake earlier this month.
The lake has 300 miles of shoreline in North Carolina, but there are no designated swimming areas and no lifeguards.