It is narrated from Makhul (may Allah have mercy on him) that the Messenger of Allah (peace and blessings be upon him) said: "When a woman dies among men and there is no other woman with them, or a man is alone among women and there is no other man with them besides him, then in that case have dry ablution (tayammum) performed on both of them and bury them; they are in the position of one who does not find water."
This is mursal.
Sinan bin Gharafah (may Allah be pleased with him) narrates from the Prophet (peace and blessings be upon him): "The man who was alone among women and died, or likewise a woman among men, with no mahram of theirs present, is to be given tayammum with earth and is not to be washed."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الجنائز / 6669