When tragedies occur, the natural inclination is to search for a prescription that will prevent future occurrences.

Such was the pursuit after a carbon monoxide leak at a Roanoke College dorm this summer killed a 91-year-old Lutheran preacher and sickened 100 other people. It was thought that if carbon monoxide detectors were installed in certain public buildings, the alarms would sense the silent, odorless killer and alert people to the danger.

Roanoke College officials thought so, and installed detectors throughout the dorms. This investment in students' and guests' well-being paid off rather quickly when a dead bird became lodged in a chimney flue, allowing the poison to accumulate inside a fraternity house. The alarm sounded, and all turned out well.

That is how it's supposed to work. Unfortunately, that isn't always the case, as a General Assembly work group found.

Studies of the detectors' performance have noted that they sometimes fail to detect the gas if the humidity level is low, an especially dangerous problem since humidity tends to be lower during the winter heating season. And the alarms go off far too often when there isn't a problem.

For these reasons, the group will recommend that lawmakers forgo passing a bill that would have required detectors in certain public buildings. Said one official, "If you require something, it builds an expectation that the device will provide some level of dependability."

He is exactly right. While manufacturers claim they have improved the detectors over the years and that some studies looked at older models, the confidence level remains low. Despite that, several states do require the alarms.

Virginia lawmakers shouldn't just shrug off the idea since the alarms, although not perfect, do hold promise in saving lives.

With carbon monoxide claiming the lives of between 500 and 1,000 Americans each year and sending about 40,000 people to emergency rooms, there is obviously a need for the government to explore better ways to protect the public. It can start by requiring more dependable alarms to ward off future tragedies.