After six children were killed, Ikea is recalling 29 million chests and dressers.

The six children were killed after the pieces of furniture toppled over and fell onto them. All of the children were three-years-old or younger. One of the children died 27 years ago, but the others were more recent between 2002 and 2016. The U.S. Consumer Product Safety Commission received reports of 36 children that were injured from the dressers as well.

The chests and dressers were unstable if they were not secured to the wall according to the safety commission. The recall applies to customers in the United States and Canada and is only applicable to certain types of Ikea chests and drawers. Ikea said the units that were recalled are children’s chests and dressers taller than 23.5 inches and adult chests and dressers taller than 29.5 inches. These units have been sold at the store for years.

For the customers that have already purchased the units, Ikea is offering free kits to attach the chests and dressers to a wall. Those that do not wish to keep the unit can ask for a refund. Refunds will be given to owners of recalled chests and dressers made between 2002 and 2016. If the units were from prior to 2002, customers can receive a store credit for half the original price.

The chests and dressers were sold with instructions saying they had to be mounted to walls the Ikea USA President Lars Petersson said. Last year, the company offered free wall-mounting kits to the owners of the chests and dressers after reports of children’s deaths.