Season 7 series finale...Season 8 first episode.

My husband and I love the show and have never missed an episode ever. We saw the stars finale last season and we watched the first episode of the new season 8 . Danny's wife Linda's died , where did that come from ? She was alive at the last episode in season 7 after the house fire. Did we miss an episode somewhere or was her death just written in? Appreciate any help on this as we're trying to see if we missed an accident or death scene...anything.