A man fatally shot a woman — believed to be his wife — before turning the weapon on himself in Lower Manhattan Monday morning, according to authorities and police sources.

The 46-year-old man shot the woman, 40, twice in the head and then blasted himself in the head on the sidewalk at Morris and Greenwich streets in the Financial District around 9:20 a.m., authorities said.

The woman was pronounced dead on scene around 9:30 a.m., and the man was rushed to NewYork-Presbyterian Lower Manhattan Hospital, where he too succumbed to his injuries about 15 minutes later.

Three shell casings and a Glock 9mm weapon were recovered on scene, police sources said.

Cops did not immediately know what led up to the shooting.