For anyone wondering, the tragedy referenced here is the death of two JC police officers. From the Wikipedia entry:

On December 25, 2005, two Jersey City police officers died while on duty after their rescue vehicle plunged into the river from the bridge. Shawn Carson and Robert Nguyen were summoned by colleagues to bring additional flares to the western approach to the bridge to better regulate traffic. Extreme weather conditions had caused poor visibility, and the gate that normally lowers when the bridge is in the open position had been malfunctioning for some time. The officers drove across the bridge and delivered the flares. They did not know that the lift span had then been raised, and as they were making their return trip, their vehicle went over the edge of the open bridge. While the body of Carsen was recovered approximately 90 minutes after the accident, that of Nguyen was not found until December 29. After an investigation the bridgetenders were cleared of any wrongdoing in January 2006. According to the NJDOT, the barrier was experiencing continuous problems due to an earlier accident, and the agency was waiting for replacement equipment to do repairs. Unsatisfied with the agency's findings, the Jersey City Police found that the NJDOT, knowing that there were problems, should not have relied on local police for public safety. A new barrier gate was eventually installed in June 2006. On May 9, 2007, the New Jersey Legislature adopted a joint resolution designating the crossing the "Shawn Carson and Robert Nguyen Memorial Bridge".

If you cross this bridge on the sidewalk or drive slowly, you will see the sign honoring them. https://imgur.com/o3ypwkD.jpg