CLEVELAND HEIGHTS, Ohio (AP) — Two sisters were killed when they were trapped on a hammock by some falling bricks at their family’s home, authorities said.

Emergency responders found Scout Scaravilli, 14, and her sister, Chasey, 12, trapped under a pile of bricks when they responded to their Cleveland Heights home around 7:45 p.m. Sunday. The girls were soon freed from the hammock and were taken to a hospital, but they were pronounced dead there a short time later.

The hammock was tied to a tree and the pillar, authorities said, but it’s still not clear what caused the pillar to collapse.

No other injuries were reported in the incident.