(CNN) -- Four firefighters were shot, two fatally, while responding to a blaze in upstate New York on Monday, and investigators believe the shooter set a trap to lure them to the scene.
The shooter, who also died, apparently took aim at the firefighters as they arrived at an early morning house and vehicle fire in the Rochester-area town of Webster, Police Chief Gerald Pickering said.
Pickering said two of the firefighters who were shot died at the scene. The two injured firefighters were hospitalized in intensive care, officials said. An off-duty police officer passing by the area also suffered shrapnel wounds, Pickering said.
Authorities did not immediately identify the shooter, who died of a gunshot wound at the scene. It was not clear whether the wound was self-inflicted, Pickering said, or why the shooter opened fire.
"We are a safe community, and to have tragedy befall us like this is just tremendous. ... You know, these people get up in the middle of the night to go put out fire," he said. "They don't expect to be shot and killed."
The shooting occurred amid a renewed gun control debate after the December 14 elementary school massacre in Newtown, Connecticut, that killed 26 people, most of them children. The gunman also apparently killed his mother and himself.
The head of a lobbying group that represents first responders said the Monday shooting was "senseless and cruel."
"The firefighters who responded today were performing a selfless, meaningful service to their community, unaware that a cold-hearted maniac was planning to ambush them and take their lives," said Harold Schaitberger, general president of the Washington-based International Association of Fire Fighters. "Coming on the heels of the horrific tragedy in Newtown, Connecticut, and on Christmas Eve, this shooting is even harder to comprehend."
New York Gov. Andrew Cuomo described the Webster shooting as "horrific." And the state's attorney general called it a "senseless tragedy"
"As this investigation unfolds, we stand with our partners in law enforcement to ensure that lethal weapons are out of the hands of dangerous people, so that brave New Yorkers who risk their lives every day to protect us are not exposed to additional danger," Attorney General Eric T. Schneiderman said in a statement.
Firefighters first arrived at the Webster fire before 6 a.m., said Rob Boutillier, the town's fire marshal.
For more than three hours, the threat of gunfire stopped them from fighting the fire and forced police SWAT teams to evacuate 33 people from homes in the area. By noon, four houses were engulfed in flames.
One firefighter escaped from the scene in his own vehicle about an hour after he was shot and was taken to a hospital by an ambulance from another location, Boutillier said. Another wounded firefighter was conscious and speaking when he was removed from the scene, he said.
The wounded firefighters were in intensive care Monday at Strong Memorial Hospital in Rochester, New York, officials said.
It was unclear what type of weapon was used in the Webster shooting.
"I know that many people are going to be asking, 'Were they assault rifles?' " I don't know that. I can't answer that at this time," Pickering told reporters.
President Barack Obama has set a January deadline for "concrete proposals" to deal with gun violence.
Sen. Dianne Feinstein, D-California, has said she will introduce legislation to reinstate the assault weapons ban that expired in 2004. The White House has said that the president supports that effort.
Speaking to reporters Friday, the head of the National Rifle Association proposed putting armed guards in schools after the mass shooting in order to protect children.
On Sunday, NRA CEO Wayne LaPierre told NBC's "Meet the Press" that he would not support new gun restrictions, saying most gun laws now on the books are rarely enforced.