The city police department has released surveillance video of an attack on two men in Manhattan.

It happened around 3:30 a.m. Thursday on Sherman Avenue near Dyckman Street in Inwood.

Investigators say the two men seen sitting in the video were catcalling a young woman on the street, leading the man walking with her to take offense.

He can be seen repeatedly hitting the men, who were 39 and 69 years old.

The 69-year-old was taken to the hospital with serious head trauma. Police sources later told NY1 that he is brain dead.

The other man was just bruised, police said.

Anyone with information on the case should contact the Crime Stoppers hotline at 1-800-577-TIPS, or text CRIMES and then enter TIP577, or visit www.nypdcrimestoppers.com