A 49-year-old woman is dead following a chain reaction crash on the Brooklyn-Queens Expressway early Monday morning and the driver who police say caused the accident is under arrest.

It happened just after 3 a.m. on the westbound side of the expressway near Meeker and Morgan Avenue in Greenpoint.

Police say the woman, identified as Aissatou Diallo, 49, was outside of her car for an unknown reason when a man in a separate car hit her car, which then knocked her off the expressway.

Diallo fell onto Meeker Avenue and was pronounced dead.

The man was taken to the hospital in unknown condition.

All lanes of the BQE have since reopened.

Police say 43-year-old Vladimir Menin of New Jersey was arrested and charged with manslaughter, aggravated vehicular homicide, DWI, reckless driving and driving without a license.