Many of the people who work in downtown Manhattan live in New Jersey, located just across the Hudson River. Yesterday, an anxious waiting had taken hold in many of the towns that dot the train lines usually carrying tens of thousands of commuters a day.

Word of who was still missing filled neighborhoods in Maplewood, about 35 minutes west of New York, as residents gathered in small groups along the town's tree-lined streets.

Among those waiting were the teachers of the South Mountain YMCA, a day-care center located right along the tracks. About 250 babies and children were dropped off at the center Tuesday morning. More than half of the children have one or both parents who work in the city.

Parents started calling almost as soon as the first plane collided with the World Trade Center. After local schools nearby started closing, teachers began the task of trying to contact parents to pick up their children -- and determining which children had parents who were unaccounted for.

As of 12:30, director Marie Papageorgis couldn't reach the parents of about 50 children. She separated the files of parents who worked in the city. By 4 p.m., the number of children with missing parents had dropped to about 10. But in her hand, she held three files of children whose parents she knew worked at the World Trade Center.

Sylvia Achee and her son Nico are among the lucky ones. Her husband, David, works at 4 World Trade Center. He called her right after the first blast, but she lost contact with him after the second blast and the collapse of the towers.

"I turned on the news," Ms. Achee said, and when she saw the collapse, "my heart fell." Another wave of calls poured into her house from people asking whether he had called again, and she almost sank in relief when he did, about an hour later. Mr. Achee had tried to help some of the injured and took a ferry across the river with a badly burned fire fighter. Ms. Achee said her husband was bruised, but otherwise all right. He was still not home as of 5 p.m.

It was only two months ago that Ms. Achee removed her son from the day-care center at the World Trade Center because, she feared lax security and that he could be a target. She also repeatedly asked her husband, a locksmith, to stop working there. "We have talked about this a lot."

Ms. Papageoris said that her staff will wait for parents -- or guardians -- as long as it takes. Other parents have volunteered to take care of any children whose parents are unaccounted for. "We are just waiting it out and hoping that somehow, everyone shows up," Ms. Papageoris said. Teachers took heart in the funny stories -- one man who was late to work at the Trade Center because his three-year-old daughter had been especially difficult. He watched the explosion from a ferry instead of being at his desk.

The task of finding parents was made considerably easier by an e-mail list the center has compiled over the last year. Many parents wrote back from Internet cafes in the city after they had evacuated or from their own computers, because the phone lines weren't working.

Virginia Brown, who has two sons at the center, already went to try to donate blood, though she found a five-hour wait. She said that many families have moved to communities such as Maplewood and South Orange in recent years because of escalating real-estate prices in Manhattan. But, she said, a tragedy like this shows how closely the suburbs and city are linked.

Selma Zupnik sat waiting at the Maplewood train station last night for her daughter, Susan, who had escaped from the 64th floor of the second tower. "The last message I got was to bring clothes," Ms. Zupnik said. She said her daughter, an analyst for the Port Authority, is scared and chilled from the showers she had to walk through when she arrived from the ferry in Hoboken. Fire officials had all the victims shower because they feared they were covered with asbestos.

Ms. Zupnik has been communicating with her daughter, who is deaf, through a wireless paging device. "I cannot wait to see her. I am thankful she is safe. But I am so sad about all the people who were killed."

Vik DeLuca, Maplewood's mayor, said that at least a few victims had been taken to area hospitals after they stumbled off of commuter trains. He feared that Maplewood and New Jersey communities would be hit hard. "There are between 2,500 and 3,000 people who go to New York every day from Maplewood, and many of them work downtown," Mr. DeLuca said. "This is going to be a very long night."

In the nearby community of Millburn, N.J., where many residents work in the financial-services industry in lower Manhattan, neighbors who on other days would casually wave to each other were milling about the streets in groups. One man, arriving home from Manhattan by midafternoon, was greeted by his wife in the driveway. The two wiped tears away as they hugged for several minutes and disappeared into their house.

Ellen Kirkwood, whose husband, Eugene, works across the street from One World Trade Center, was attending the first Parent-Teacher Organization meeting of the year at Wyoming Elementary School in Millburn yesterday morning when the principal made an announcement.

"She said there was some kind of incident in New York," said Mrs. Kirkwood, whose son was in kindergarten class. "I wasn't really paying much attention, but then she said something about the World Trade Center, and I got up and left," along with several other people. She tried to call her husband from the school and couldn't get through, so she picked up her one-year-old and three-year-old from the baby sitter and headed home.

Her husband, meanwhile, was at the trading desk at Smith Barney Asset Management on the 43rd floor of 7 World Trade Center when the first plane hit. "The building shook for a long time, and we looked out the window and saw debris falling down and fire all over the place." Mr. Kirkwood said some people in the office started crying, and then someone on the desk told everyone to get out.

Outside, Mr. Kirkwood started heading toward the ferry. "I stopped to talk to someone I recognized and looked up saw a plane bank and go right into the other tower," Mr. Kirkwood said. At that point he knew it was intentional, and said to the other person, "Let's get out of here."

On the ferry to New Jersey, Mr. Kirkwood said everyone stared back toward Manhattan "in shock." He managed to get through on his cellphone to his home and left a message that he was OK. Back in Millburn, Mrs. Kirkwood arrived at home with her two children from the P-TO meeting and heard the message from her husband. "I was pretty together, but I was still very relieved." Mr. Kirkwood arrived home a little later, and by late afternoon news reports said that his building also had collapsed.

For many children, the news quickly turned from disbelief to anxiety over what might have happened to their parents who work in New York City. As word spread, schools called special assemblies and tried to help students contact their families by telephone and by e-mail. At Pelham Middle School in Pelham, N.Y., a small suburb just outside New York City with a heavy population of Wall Street traders, investment bankers and brokers who work in or near the World Trade Center, some children were crying after failing repeatedly to contact their parents' cell phones or offices.

One student at Pelham High School was called to the office in the early morning and went home after being told that his father, a bond trader, worked on the floor that the first plane hit. By late afternoon, there was still no word of his fate.

"At first I assumed it was an accident. Once we had heard that the Pentagon had been hit, and a second plane crashed in, everybody knew it was a terrorist attack," said Jesse Strauss, a 13-year-old eighth-grader at the school. "Throughout the day, everybody wanted to get out of school as soon as possible and get home and see if their parents were all right.

"I'm still in the shock that somebody would do something like this and that this could really happen," Jesse said. "You just thought America was the safest country. . . . I think people will be more cautious and won't assume nothing will happen because it can." His mother echoed his concern, "Our world as we know it isn't going to be that way for a long time," Lorrie Strauss said. "I was so scared, because I didn't know where my dad was," said Elizabeth Geiger, at student at Ursuline Academy in New Rochelle, N.Y.

Hunter Blakely, a sixth-grader at Pelham Middle School, said, "I was feeling petrified. I thought my Mom was there and that we were going into a war and that we could get bombed at night." People worried about neighbors and friends who worked in the World Trade Center. They greeted each other with relief and exclamations of, "Thank God you're OK."

In Rockville Centre, N.Y., a Long Island suburb of New York City, the train station was unusually silent in the afternoon, because commuters weren't coming home because of canceled trains. A hastily erected marquee-type sign at the station advised residents of the urgent need for blood.

Nearby, at a blood bank affiliated with Long Island Blood Services, so many donors had volunteered that officials were accepting only donors with O-negative blood type, known as universal donors since their blood is accepted by any recipient. Donors with other types of blood were told to return later, or go to nearby hospitals or a Marriott hotel that were conducting blood drives over the next few days, said Susan Arnold, R.N., unit manager for Long Island Blood Services.

Ms. Arnold directed staffers and volunteers, carrying ice into the building, while answering questions from a cancer survivor about whether she could donate blood. More than 100 donors had already given blood, Ms. Arnold said. Dozens more took numbers and sat on folding chairs that wrapped around the building, waiting their turn. In the street out front, volunteers suggested to people without O-negative blood could donate at a later time -- to ease possible future shortages, since donated blood has a shelf life of only a month, and donors must wait 56 days before donating again. Local restaurants donated food and drinks for the blood donors and blood-bank workers.

The mood was mostly solemn and determined, but signs of anger were also in evidence.

In nearby Oceanside, commuters who did straggle home through the day were greeted by neighbors with exclamations of relief at their safe return, and anxious questions about those who had yet to come home.