Congress needs to pass legislation banning the sales of pressure cookers...or at least requiring background checks on anyone trying to purchase them. Limiting the capacity to only 3 liters would also be helpful.
Keep in mind, the pressure cookers used in the Boston Marathon bombings had a 6 liter capacity. Limiting the capacity to only 3 liters would have significantly reduced the number of casualties. Think about it, its not rocket science. Just my tongue-in-cheek opinion.