(CNN) -- The staff at the Hands and Feet Mission in Jacmel, Haiti, is worried. Not about looters; they are worried about the aftershocks.
They just won't stop. The children of the orphanage, who range in age from 2 months to 9 years old, panic every time one comes. The situation is overwhelming for them.
At times they are normal kids, laughing and playing marbles, and then their emotions swing violently, and they run into the yard, screaming and crying.
The good news is that everyone with the mission is physically OK. Mark Stuart, former lead singer for the Christian group Audio Adrenaline, said Wednesday that they will sleep outside again to protect the kids from the potential of falling concrete.
The missionaries and the children put down sheets and towels in the dirt Tuesday night, but no one slept well. Through the night, the tremors continued.
They can still consider themselves lucky. Stuart says many nearby buildings are destroyed, and many people were killed.
"I ventured out immediately after the quake and the streets were filled with panicking people," he said via e-mail. "The traffic was very dangerous and within a five-minute walk from our village in Cyvadier, I witnessed four collapsed houses and a hotel. Thank God most of the Haitians spend a lot of time outdoors. Most of the injuries around here came from the hospital, school, and hotels."
He said the loss of life in Jacmel, on Haiti's southern coast, was "substantial."
Stuart has been visiting Haiti for many years and established the mission along with his former bandmates in 2004. The orphanage now has more than 40 children it cares for.
Stuart's cell phone isn't working, so he has to update family and friends through the Internet. He says the Haitian people have being heroic.
"I think the locals are reacting as good as they can be," he writes. "I was here during Hurricane Hannah and it's sad to say, but they are very used to tragedy."
There is an airport in Jacmel, and many residents -- perhaps thousands -- have traveled there to get help from the UN. No one is looting, as far as Stuart knows.
But the people are terrified, scared that another major quake will hit and they will be killed. Sleeping is difficult. Everyone is exhausted. And they want to know why it happened to them.
"I'm left wondering why this nation is so tied to tragedy. Please pray for all of Haiti tonight," Stuart writes.
Throughout Haiti, earthquake survivors describe destruction and fears for people trapped beneath the rubble.
CNN iReporter Carel Pedre was driving when the 7.0-magnitude earthquake struck Tuesday evening. Suddenly, debris blocked the road, and he got a sense of the devastation when he started walking.
People thought it was the end of the world, he said.
"I heard a lot of people praying, saying that Jesus is coming, saying that we need to pray, we need to save our lives by believing in God," Pedre said.
He saw collapsed buildings every few feet, he said, and people -- mainly children -- with head injuries.
Travel agent Jacqualine Labrom said some people were in a "state of hysteria," perhaps because they had never seen an earthquake of this magnitude.
A local hospital brought patients outside and laid them on the ground, Labrom said.
"A popular church had completely collapsed, having folded in on itself and other houses and walls were down," Labrom said by e-mail. "People were wailing and crying and didn't know what to do. They said that although there had not been a service there were some people inside the church praying or having a meeting and they were sure that if they hadn't already died they were seriously injured."
Pictures from Haiti showed broken and flattened concrete buildings. People in the streets were dusty from the concrete and bloody from their injuries.
"One woman, I could only see her head and the rest of her body was trapped under a block wall," said iReporter Jonathan de la Durantaye, who drove through the capital of Port-au-Prince after the quake. "I think she was dead. She had blood coming out of her eyes and nose and ears."
The earthquake sent a cloud of dust over Port-au-Prince. Beneath it, people were screaming, running out of buildings, tending to victims and calling for help.
"What I can hear is very distressed people all around in the neighborhoods that we are in," said Ian Rogers of the charity Save the Children. "There is a lot of distress and wailing of people trying to find the loved ones who are trapped under buildings and rubble."
Dust tipped off one man in Port-au-Prince to the devastation that lay outside his door, said Gregory von Schoyck of the Haitian-American Friendship Foundation.
"He is a missionary pilot, and he wrote to say that his refrigerator walked across the room about 4 feet and his dishes rattled a lot," von Schoyck said from a town just northeast of Port-au-Prince. "But when he went outside, he said, the air was full of dust, and he said that could only mean one thing: that a lot of buildings must have gone down."
Von Schoyck said he felt the pitching of the ground, and even his sturdy stone house "was groaning and moaning a little bit" during the quake.
Haitians fear that survivors stuck inside collapsed buildings may soon become victims. Pedre said. The Western Hemisphere's poorest country is not equipped to rescue those trapped in one building, let alone hundreds.
When a single school collapsed in November 2008, all 150 people inside were trapped and died because authorities lacked the proper equipment to rescue them, Pedre said. He questioned how the country could deal with this large-scale disaster.
"That was one school in 2008. Now it's every step, you have a big building that collapsed," he said. "There are a lot of people under those buildings still living, still breathing, but no response to help them get out of where they are."
Clay Cook said his daughter, who works at a mission in Haiti, was briefly trapped at home after the quake. Three staff workers and her husband managed to free her from the concrete, he said.
Cook called the rescue "heroic." His son-in-law drove eight hours through the night to help free her, he said.
For many, just getting to the capital is a challenge, said the Rev. Louis St. Germain of Good Shepherd Presbyterian Church in Les Cayes, on Haiti's southern coast.
"At the moment, we have no way to contact Port-au-Prince," he said. "The only way we can go to Port-au-Prince is by car or by motorbike, but when you reach Port-au-Prince, you have to leave it because the streets are really impassable."