Yes, they were waiting for a Delta flight to JFK. They were brother and sister.
"Alexander and Sascha Pinczowski were siblings living in Belgium, but they never lingered in one place for long. The children of a hotel manager, they had lived in Turkey, Greece and Germany, and were on their way back to New York, a city they both loved, when they arrived at the departures hall at Brussels Airport on Tuesday.
Mr. Pinczowski was going to meet his fiancée in New York, where he and his sister recently lived, so they could attend a wedding together in North Carolina. His sister was planning to spend the weekend with friends. They were standing in the Delta ticket line and were on the phone with their mother, Marjan Pinczowski-Fasbender, when two bombs exploded."
More here:
http://www.nytimes.com/2016/03/26/world/europe/alexander-and-sascha-pinczowski-siblings-on-way-to-new-york-killed-at-brussels-airport.html?_r=0