What a shame! / How sad! / What a pity!
Expresses sympathy, disappointment, or regret about a situation. Tone ranges from genuinely sad to mildly inconvenient depending on context.
—She couldn't come to the party. —What a shame!
What a pity you're not staying longer!
—It's raining on the wedding day. —What a shame!
—I couldn't go to the party. —What a shame.
What a shame you didn't meet him.