WASHINGTON — More than 2.1 million drop-side cribs by Stork Craft Manufacturing are being recalled, the biggest crib recall in U.S history, following reports of four infant suffocations.

The Consumer Product Safety Commission said yesterday the recall involves 1.2 million cribs in the United States and almost 1 million in Canada, where Stork Craft is based. Sales of the cribs being recalled go back to 1993.

Nearly 150,000 carry the Fisher-Price logo.

The CPSC said it is aware of four infants who suffocated in the drop-side cribs, which have a side that moves up and down to allow parents to lift children from the cribs more easily. The agency also said there have been 110 incidents of drop-sides detaching from the cribs.

The Stork Craft cribs have had problems with their hardware, which can break, deform or become missing after years. CPSC said there can also be problems with assembly mistakes by the crib owner. These problems can cause the drop-side to detach, creating a dangerous space where a child can be trapped.

The commission is urging parents to stop using the cribs until receiving a free repair kit from Stork Craft. The kit will convert the drop-side into a fixed side.

The cribs, distributed from January 1993 to October 2009, were sold at major retailers including BJ's Wholesale Club, Sears and Walmart stores, and online through Target and Costco. They sold for $100 to $400, and were made in Canada, China and Indonesia.