The city Department of Buildings has issued three violations to the demolition company that was working on an Upper West Side building that partially collapsed Thursday morning, injuring six passersby and five firefighters.

A 7-month-old infant is among the six people injured in the incident, which occurred at a demolition site on the west side of Broadway between 99th and 100th streets. All are listed in stable condition at area hospitals.

All of the construction workers at the site have also been accounted for, and none of them were injured.

A Gristede's supermarket was being torn down to make way for a high rise apartment building when it collapsed just after 9 a.m. Officials say a construction worker was using a back hoe on the one-story building when the hoe crashed through the roof.

The front wall, which was just a shell, collapsed, taking the scaffolding with it and trapping pedestrians under the rubble.

The DOB has issued three violations to Safeway Environmental Corporation, the company doing the demolition at the site. The violations cite the company for unsafe demolition, failure to remove the building's heating, ventilation and air-conditioning systems, and use of mechanical equipment for which a permit had not been issued.

The DOB is also halting work at several other Safeway sites.

"We're doing a full investigation of what happened and what caused the collapse, and then we’ll figure out what steps to take going forward," said DOB Commissioner Patricia Lancaster.

At least 30 FDNY units responded to the collapse. Firefighters quickly sifted through the rubble and collapsed scaffolding around the building looking for victims.

"I heard a loud crash, I looked up, I saw the wall had fallen," said one witness. "A bunch of civilians were coming out of the diner and out of the smoke shop so I threw my jacket off and ran over and there was an arm sticking out of the debris. We started quickly clearing the debris. The construction crew came out from the site, started to help clearing, pulled out a woman yelling, 'My baby, my baby!' We could see a wheel of a stroller, so we started clearing on the way toward the stroller. On the way we found a pocket and we picked up some more debris and there was a man there. We just all worked really quickly together."

"I turned around as I was picking up the phone and the whole building was collapsing. It was just rubble," said another. "About three or four feet behind me there was a woman who was half pinned in and out of the rubble — there was rubble all over her. Everybody came and ran across the street and from around and we all pulled her out, and as I said, she was just screaming for her baby and at that point everybody went nuts. I think there were some off-duty paramedics because they were right here and they right in there and they pulled the baby out. The baby looked like it was blue."

In addition to the injured baby, three women and two men were injured in the collapse, including a man who broke both arms and both legs. Five firefighters were also injured, including one who injured his ankle at the site of the collapse.

The MTA briefly suspended service on the No's. 1, 2, and 3 line running through the area on the request of the FDNY, but service was restored at around 11 a.m.

Fire Commissioner Nicholas Scoppetta, speaking at a press conference following the collapse, said trains will be running at no more than five miles an hour so as not to create vibrations that might cause any further collapse of weakened structures in the area.

Extell Development Corporation has plans to erect a 31-story apartment building at the site of today's collapse, and a 37-story building across the street on the east side.

In a statement, Extell called Safeway one of the city's premier demolition companies. It went on to say: "At this point our sole concern is the safety of all concerned, especially those who were reported injured. We are of course cooperating with all appropriate city agencies investigating this incident."

The DOB says Extell has all the proper permits for the demolition site where the collapse occurred. However, it has still issued the company a stop work order for that site, as well as the site across the street where the 37-story apartment building is to be constructed.

As recently as Wednesday night, neighborhood advocates protested the construction plans, saying the skyscrapers were not in keeping with the character of the neighborhood. The tallest building on the block is 20 stories.