The department is investigating some calls about streets that people say weren't covered, said spokesman Keith Mellis. In some cases, it could be that drivers who dug out their cars left behind mounds of snow and then "it looks like the street hasn't been plowed at all," he said.
Not all the streets are completely clear but they were passable, Mellis said, adding that sanitation crews would continue to plow throughout the day and put snow melters around the city to clear the towering piles of snow created by the plows.
Report: Disgruntled Workers Slowed NYC Cleanup
The unplowed streets and abandoned cars during and after the storm hampered the city's emergency response system, which dealt with a staggering number of calls, and Mayor Michael Bloomberg suggested Wednesday that New Yorkers themselves shared some of the blame.
"We asked the public to do two things," Bloomberg said. "Don't call 911 unless it was a serious emergency ... and don't drive.
"Unfortunately, too many people didn't listen."
New York City operators fielded 49,478 calls to 911 on Monday, the day after the storm. That total was the sixth highest in any day since the city began keeping statistics. There were 38,000 calls Tuesday. Some of the calls came from the same location, but it's not clear how many.
Many of the calls were not for emergencies, and plows couldn't clear the way for ambulances because streets were clogged with abandoned vehicles.
"Your car stuck in the middle of the road made things worse," Bloomberg said.
In some instances, it took hours to respond to requests for help.
The FDNY said additional ambulances were on the road and extra firefighters were working, but it wasn't enough to handle the call load, which was backlogged by 1,300 at one point.
Among the calls was a Brooklyn woman who called 911 several times on Monday to report she was in labor. She delivered a baby that was unconscious and later pronounced dead.
Initially, dispatchers assigned the call a low priority because the expectant mother hadn't reported that either she or the baby were in distress, and her delivery was not believed to be imminent. Dispatchers called back several times to check in on the woman, and when a call came in that the newborn was unconscious, the priority was upgraded and EMS workers responded 12 minutes later. The infant was pronounced dead at a hospital. The medical examiner will determine a cause of death.
In another case, Laura Freeman's 75-year-old mother died while waiting three hours for an ambulance to reach their Queens home.
"They said 'It was stuck down the block. We had to come walking down a block and a half with our equipment. I'm so sorry.' And I don't blame them," Freeman told WABC.
On Wednesday, as stories began to surface about people who may have suffered serious medical problems while waiting for ambulances, the mayor was his most apologetic, without actually apologizing.
"We did not do as good a job as we wanted to do or as the city has a right to expect, and there's no question - we are an administration that has been built on accountability," he said. "When it works, it works and we take credit, and when it doesn't work, we stand up there and say, `OK, we did it. We'll try to find out what went wrong."'
The fire department trains firefighters and emergency medical services workers on driving in all types of weather. Firefighters put shovels and salt aboard engines to help clear roads and snow chains to plow through snowy streets.
But ambulances can't be outfitted with snow chains because it would damage the vehicles. Plus, ambulance drivers are trained to try to get as close to the emergency as possible, because they carry heavy gear - and sometimes heavy patients.
Most of the calls with long wait times were not emergencies. The FDNY ranks emergencies and responds based on need, so a lesser emergency would be shelved until there was time to respond.
Bloomberg already has directed Skip Funk, the new citywide director of emergency communications, to look at why the communications and dispatching system failed.
"I'm extremely dissatisfied with the way our emergency response systems performed," he said Wednesday during a news conference in the Bronx.
He said he was especially disturbed by reports that ambulances had gotten stuck trying to drive through deep snow.
"Could we do a better job? We're going to try and find out. Could our ambulances have taken different routes? We're looking at that. Perhaps they could have stayed further away and walked to the places rather than try and get down the secondary roads."
At New York's airports, there's finally hope for stranded passengers. Most flights are now on time but airlines can't find seats for the overflow of all those displaced travelers, reports CBS News correspondent Michelle Miller.