The word came with U.S. Secretary of State John Kerry visiting Brussels to express his condolences to the Belgian people.
In addition, family members said a brother and sister, both Dutch citizens who had been living in New York City and were among those missing following the Brussels attacks, were killed, their family says.
Sascha and Alexander Pinczowski have relatives in the Netherlands. They were returning to the U.S. when they lost their lives, CBS News was told.