A 7-year-old Loudoun County girl was killed over the weekend after a tree fell on her, according to authorities and a relative.

Two children were swinging in a hammock tied to a tree when the tree fell on both, according to the county sheriff’s office.

The incident, which the sheriff’s office called “a tragic accident,” occurred about 6 p.m. Saturday at a family gathering at a house on St. Francis Court in the Purcellville area.

It was not clear why the tree fell. No explanation was available.

After the accident, the girl was flown to Inova Fairfax Hospital, where she died, the sheriff’s office said.

The second child, an 8-year-old boy, suffered injuries described as minor, the sheriff’s office said.

The girl was identified by a relative as Sabina Surjit Henderson.

A family statement described Sabina as a smart and witty child who loved telling jokes and making others laugh.

The statement said she “showed amazing kindness and thoughtfulness to her friends and her family, and was loved by all who knew her.”