A second police officer caught in a teenager's deadly ambush outside a suburban Washington, D.C., stationhouse died early Wednesday, authorities said.

Master Police Officer Michael Garbarino, 53, had been hospitalized for the past week in critical condition and died at 2:45 a.m., Fairfax County police said. He had been shot five times when the heavily armed teen opened fire outside a Chantilly police station May 8.

"Our family has again suffered a tremendous loss," said Fairfax County Police Chief David M. Rohrer.

Police said Michael W. Kennedy, 18, fired off at least 70 rounds in the station's parking lot before he was killed. He was armed with a high-powered hunting rifle, five pistols and an AK-47-style assault weapon, authorities said.

Garbarino was sitting in his police cruiser at the end of his shift when Kennedy drove up in a hijacked van and began firing. He managed to call for help, even after Kennedy had fired at least 12 shots at his cruiser, police said.

Detective Vicky Armel, 40, died the day of the attack and was buried Saturday after a funeral with full police honors. A third officer was treated for minor injuries.

Armel and Garbarino were the first officers shot and killed on duty in the department's 77-year history.

Wednesday morning, entrances to the police station and a patrol car were draped in black bunting as a memorial to Garbarino. Officers placed bouquets of flowers and a small white teddy bear on the vehicle's hood and trunk. As a master police officer and 23-year veteran of the police force, Garbarino had mentored and trained other officers.

Residents also stopped by to pay their respects.

"I came to pray," said Shawnee Ryan, 37, of Fairfax, as her toddler son sat quietly in his stroller. "Prayer is the only gesture that seems fitting."

Police have not spoken with Kennedy's family since the ambush, but Lt. Rich Perez, a police spokesman, said they want to talk to the parents to learn more about what may have led to the shooting.

Authorities said Kennedy had recently been arrested on carjacking charges and had attempted another carjacking that day. The troubled teenager had also told friends more than a year ago that he planned to shoot up a police station.