An accident involving a backyard hammock left two sisters, a 14-year-old and a 12-year-old from the Cleveland area dead.

According to rescuers who went to the scene, the hammock had apparently been affixed to a tree and to what authorities described as a brick column. The brick column had collapsed on the girls as they were both lying in the hammock.

While those who responded were able to pull the girls from the rubble and take them to a nearby hospital, they both later succumbed to their injuries.

Authorities said that they will continue to investigate the accident. At this point, they did not have an explanation for how a brick column would collapse without warning.

However common they may be, brick walls are actually detailed engineering feats. The building supplies themselves must be of quality. Mistakes in their construction or repair can lead to serious problems, including a sudden and potentially tragic collapse.

Likewise, the person or firm who assembles the wall must follow safety standards and must be sure that they follow all the steps they need to in order to make sure the structure will hold. Those who inspect or repair brick structure need to exercise the same degree of caution and responsibility.

Depending on the outcome of the investigation, it may become clear that an engineer, repair person or other professional was negligent and contributed to this horrible accident. It is also quite possible that something was wrong with the structure itself, and that could mean the family of these kids will be able to file a product liability case.