Well, Rhode Island Reds are generally longer lived than that in terms of productive life, but, hatcheries often sell poor quality versions of that breed which are basically very similar to most commercial layers --- heavy producers for only two years on average. Depending on what sort of RIR you've got, that may be your issue. But it could also be a moulting issue, if they've not moulted once a year before this that could be the issue too.
Some of these breeds have been developed to not go into moult at any normal times, so they lay until they're culled at two years old without stopping to moult. If they've never moulted before, then they'd be long overdue and in my experience heavy laying hens who moult late are often so overworked by that stage that they take a very, very long break before laying again.
(I prefer mongrels who take small, yearly breaks, moult normally, and lay well for many years to come over hens who remain in a constant state of overproduction before becoming exhausted and dying prematurely aged or quitting production altogether).
But that's more common for production layer breeds and hybrids than heritage breeds like RIRs. Depends where you got them I guess. Pics would help people tell what sort of genetics they have, which could help deduce potential production longevity, as hatchery RIRs don't tend to look like the 'official' breed nor have the same qualities. Even someone breeding beautiful birds can be totally omitting to select for the production characteristics they're also supposed to have, just because it may be show quality doesn't mean it will perform like the breed used to be renowned for... In fact if they're show quality they're generally less likely to have any other traits they're supposed to. That's all a lot of conjecture anyway, may not be relevant to your birds, for all I know they had a dog or fox scare them and went off the lay for a bit.
Best wishes.
