(CNN) -- A display board at an Alabama airport crashed down Friday, killing a child underneath and leaving at least one other person in critical condition, hospital and airport officials said.
The large digital sign -- showing when and where flights were arriving to and departing -- collapsed around 1:30 p.m. (2:30 p.m. ET) inside Birmingham-Shuttlesworth International Airport, airport spokeswoman Toni Herrera-Bast said.
It fell on multiple people who were transported to area hospitals.
One of them, Luke Bressette, died from his injuries, said Justin Cohen with Children's of Alabama. The boy's age was not immediately known, but officials described him as a child.
At least one person is in critical condition at UAB Hospital, hospital spokeswoman Megan Davis said.
Larry Snyder was riding up the escalator when he saw the display board fall, telling CNN affiliate WIAT that one family was especially affected.
"The family was crushed, little kids crushed underneath the sign. And everybody was scattering to lift it up," Snyder said, adding that he was among those who helped.
Video footage showed people sweeping up the area and a cut-out spot on a wall with protruding wires.
As of early Friday evening, authorities didn't know why the board fell, according to Herrera-Bast.
The incident happened in a new part of the airport, in a public area before security checkpoints. According to CNN affiliate WVTM, the area opened up March 13 and includes a covered parking deck, children's play area, eating establishments, a new baggage system and other features.
CNN's Greg Botelho and Ryan Rios contributed to this report.