We describe 4-dimensional complex projective manifolds X admitting a simple normal crossing divisor of the form A+B among their hyperplane sections, both components A and B having sectional genus zero. Let L be the hyperplane bundle. Up to exchanging the two components, (X, L, A, B) is one of the following: 1) (X, L) is a scroll over \bm{P}
1 with A itself a scroll and B a fibre, 2) (X, L)=(\bm{P}
2× \bm{P}
2, \mathcal{O}_{\bm{P}
2× \bm{P}
2}(1, 1)) with A∈|\mathcal{O}_{\bm{P}
2× \bm{P}
2}(1, 0)|, B∈|\mathcal{O}_{\bm{P}
2× \bm{P}
2}(0, 1)|, 3) X=\bm{P}_{\bm{P}
2}(\mathscr{V}) where \mathscr{V}=\mathcal{O}_{\bm{P}
2}(1)
oplus 2oplus \mathcal{O}_{\bm{P}
2}(2), L is the tautological line bundle, A=P_{\bm{P}
2}(\mathcal{O}_{\bm{P}
2}(1)
oplus 2), and B∈π
*|\mathcal{O}_{\bm{P}
2}(2)|, where π: X→ \bm{P}
2 is the scroll projection. This supplements a recent result of Chandler, Howard, and Sommese.
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