In 2003, just months into his job with the Rockville Volunteer Fire Department, Sander B. Cohen was credited with helping three residents of an apartment building escape a fire. He was 19.

A year later, Cohen and four of his colleagues would be awarded a citation for bravery, the highest recognition given to firefighters and police officers.

On Saturday, Cohen's willingness to put duty first was being heralded again, but this time it was accompanied by grief.

Cohen was driving on Interstate 270 near Falls Road in Montgomery County about 10 p.m. Friday when he pulled to the side of the road to help a motorist.

Both he and the driver, an FBI agent, were killed when a car struck them, sending them over a concrete barrier. Cohen was then hit by another vehicle.

During a news conference at the Maryland State Police barracks in Rockville, visibly shaken law enforcement officers announced the death of Cohen, 33, a deputy chief state fire marshal and a lieutenant with the city's volunteer fire department, and Carlos Wolff, 36, an FBI supervisory special agent in the D.C. office.

Jim Vagonis, chief of the volunteer fire department, said Cohen "dedicated his entire life" to helping people. He said the 2003 fire was an example of what kind of man Cohen was.

He was "just a kid out there trying to help people," Vagonis said of the then-19-year-old. "He was a doer."

He added: "He was dedicated to helping those in distress. That's just who he was."

In a statement released late Saturday from Wolff's family, the FBI agent was called "an amazing father, husband, uncle and brother who made us all very proud.

" He loved serving his country as a part of the FBI. He was always so helpful and giving, not just to his friends but strangers too. Our hearts are broken. We appreciate your prayers during this difficult time."

Carlos Wolff, an FBI supervisory special agent in the D.C. office.

According to the statement, Wolff was married and the couple had a son, 7, and a daughter, 2. Wolff also had five siblings, the statement said.

FBI special agent Gordon Johnson described Wolff as an 11-year member of the agency who was assigned to the criminal investigative unit.

"The loss will be felt by the entire FBI family," Johnson said. He added, "This is an extremely sad day for all of us who are sworn to protect the community."

Authorities said Wolff was driving an Acura sport-utility vehicle southbound in the fast lane when he apparently struck a median wall, leaving his vehicle disabled and partly in the road. Cohen, who was off duty, saw the disabled vehicle, called into the Rockville barrack and reported the accident.

Cohen pulled his vehicle behind the Acura and turned on his hazard lights. Both Cohen and Wolff were standing on the shoulder behind Wolff's vehicle when the driver of a Honda Accord struck them, authorities said.

The men were thrown over the concrete wall into the northbound lane. Cohen was struck again by a vehicle traveling northbound, authorities said.

Cohen was pronounced dead at the scene. Wolff was taken to Suburban Hospital in Bethesda, where he was pronounced dead. The driver of the Honda, as well as two passengers in his vehicle, were taken to hospitals with injuries that were not life-threatening.

Police said it is unclear why Wolff's vehicle hit the wall. It also is unclear what caused the Honda to strike Cohen and Wolff.

The driver of the Honda remained at the scene until he was taken to a hospital. The driver in the northbound lane who struck Cohen also remained at the scene. No charges have been filed.

Police said their preliminary investigation did not indicate that alcohol was a factor in the three accidents.

Weather did not appear to have been a factor either, said Greg Shipley, a Maryland State Police spokesman. He noted that it did not begin to snow until Saturday morning.

Shipley reminded drivers to "always remain alert."

Authorities noted that even though Cohen was off duty at the time of the accident, his actions were those of someone performing an official duty. His death will be considered one that occurred in the line of duty.