UPDATED as of 12:40 a.m. on 10/21/2015

NEW YORK (CBSNewYork/AP) — An NYPD officer was shot and killed in East Harlem Tuesday night, NYPD Commissioner Bill Bratton said.

“We’re all in mourning. The whole city is in mourning,” Mayor Bill de Blasio said.

The shooting happened around 8:30 p.m. near the Robert Wagner Houses at East 120th Street near FDR Drive.

As CBS2’s Tony Aiello reported, traffic was a mess on the east side of Manhattan as the FDR was transformed into a crime scene.

Bratton said police had been investigating a report of shots fired near 102nd Street and FDR Drive.

Upon arrival, a victim reported a bicycle had been stolen, police said.

Bratton said officers encountered a suspect at East 120th Street and there was an exchange of gunfire.

A male police officer, identified as 33-year-old Randolph Holder, was shot in the head and rushed to Harlem Hospital Center in critical condition, but later died of his injuries.

Police said a suspect suffered gunshot wounds to his leg and was apprehended by police. He is expected to be released from the hospital later Wednesday morning and taken into police custody.

A gun was recovered at the scene of the shooting, police sources told CBS2.

Bratton said Holder was a five-year veteran with the NYPD, starting with the department in July of 2010.

He said Holder’s family is from Guyana, where his father and grandfather were both police officers.

“We just had the unfortunate responsibility to tell a father his son is never coming home,” said Police Benevolent Association President Patrick Lynch.

Bratton said this is the fourth police officer death in the last 11 months, and that’s “as bad as it gets.”

Police activity closed the FDR Drive in both directions between 96th and 125th streets for hours Tuesday night. Authorities warned to expect extensive delays and seek alternative routes if possible.

More: Check Traffic

Drivers and passengers were going nowhere, and took to social media to post pictures and video of the stuck cars and the frantic rush of first responders.

“I was on my way home from work and all of a sudden I just saw police cars coming from everywhere,” Moish Levine said.

Amid the intense search, some passengers stuck in taxis and livery cabs decided to walk off the FDR to Second Avenue in search of another ride home.

(TM and © Copyright 2015 CBS Radio Inc. and its relevant subsidiaries. CBS RADIO and EYE Logo TM and Copyright 2015 CBS Broadcasting Inc. Used under license. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed. The Associated Press contributed to this report.)