An 11-year-old Annandale boy was accidentally killed by a 10-year-old friend last weekend, adding the names of two more boys to the long, long list of America's children who have had their lives ended or indelibly scarred by handguns. The story was chillingly familiar: The Boys shomehow found the gun in a locked drawer of the younger boy's home and loaded it, and the 11-year-old was struck by a single bullet to the head.

Last year, the select panel for the promotion of child health of the Health and Human Services Department said the handgun was responsible "for a virtual epidemic of deaths and injuries among children and youth." It said that handguns are found in about 20 percent of American households and that in 1977 gun accidents were the fifth-ranking cause of accidental deaths among children under 15.

If handguns are found in 20 percent of America's households, it means that 20 percent of America's households are deadly places. They are deadly for adults who, in fits of rage, are more likely to kill or maim each other with handguns than they might be if left to vent their fury with their fists, and they are deadly for children who find the guns. Handguns were used in 11,522 of the 23,044 murders committed in this country last year, according to the National Coalition to Ban Handguns.

Efforts to ban the manufacture and sale of handguns have gained tremendous momentum during the last several years. Morton Grove, a little town in Illinois that passed a stiff local ordinance banning the possession of firearms, has become a battle ground and a battle cry in the war between the National Rifle Association and the handgun control lobby. Both sides are watching closely to see whether the ordinance is upheld in court, and both are saying that if the ordinance is upheld, it can serve as a model for victory or defeat of local handgun control across the country.

The potential liability of gun manufacturers and sellers is emerging as a new front in the war on handguns, according to an article in the November issue of The Brief, a magazine published by the American Bar Association. The theory behind the argument is that manufacturers and sellers can be held responsible for injuries caused by guns, not only when they are defective, but also when they function the way their owners want them to, namely to cause harm.

Stuart Speiser, a New York City lawyer and author of a book called "Lawsuit," predicts that successful litigation holding manufacturers responsible for gun injuries and deaths would put manufacturers in a position of either going out of business or acting in the interests of public safety. "There's no reason why manufacturers could not limit the sale to people with driver's licenses, certificates of good character, no police record and a reason to have a gun, and make them wait a few days before getting it."

The outcomes of the Morton Grove battle and legal suits against manufacturers are a long way off. In the meantime, guns are still in private homes and children are still imperiled. Accidents involving them, which happen daily across the country, raise fundamental legal and moral questions about the obligations gun owners have to protect the lives of children who might be playing in their homes. People who own open swimming pools and vicious dogs can be held liable for negligence. So should negligent gun owners.

Do gun owners fulfil their obligation toward the safety of others merely by locking guns up or merely by putting ammunition in one place and the guns somewhere else? Are guns that are stored in the same proximity as the ammunition really unloaded guns? Have gun owners taken every reasonable precaution against their gun harming someone when they lock up the guns but put the key nearby or let their children know where the key is? These are legal questions that are beginning to be asked, and at least one negligence suit involving the death of a 3-year-old has been filed in Texas. If the families of children who are killed or injured by firearms in their homes were to begin winning suits against the gun owners who are found to be negligent, people might think twice about their need to have guns in their homes.

There are also moral questions about the obligations of people owning guns around children. Certainly guns should be locked up and certainly the ammunition should be stored away from the guns. But gun owners also have a moral obligation to let others know they have a deadly weapon in their homes. The gun-owning parents ought to inform the parents of their children's playmates that their children are playing in a home where there is a gun.

To some parents, that won't make a difference. But parents who don't keep a gun in their own home and who don't want their children in homes with guns have the right to that information.

The parents of the child who died in Annandale were longtime advocates of handgun control. Had they known their neighbor owned a gun, they might have had a chance to protect their child from it.