Tragedy struck in Denver, North Carolina this weekend, as two children died in an accident at a construction site.

According to a report from Charlotte ABC affiliate WBTV, two children were playing in a dirt pit when a dirt wall collapsed on them. James Caldwell, age 7, and Chloe Arwood, age 6, were buried beneath thousands of pounds of dirt in the incident.

Caldwell’s father, who was working at the construction site, called police, who began efforts to dig the children out of the 24-feet deep pit. The search for the children lasted through the night, with around 75 rescue workers digging non-stop. The children’s bodies were located early Monday morning.

Neighbors have told WBTV that the children were cousins. The basement for a house was being dug out at the construction site at the time of the event.