Tokyo (CNN) -- He's lived in Japan for nine years and is no stranger to earthquakes. But Ryan McDonald said this one terrified him.
"Oh my God, the building's going to fall!" the English teacher shouted on a video he sent to CNN's iReport, as he filmed the scene outside his home in Fukushima on Friday during the worst earthquake to hit Japan in recorded history.
About 250 kilometers (155 miles) away in Ichihara, August Armbrister wrote that "night came quickly today" as an earthquake-sparked refinery fire there sent thick black smoke upward, blocking out the blue sky.
The aftershocks were the worst, Harrison Payton said.
"They feel like the entire world is a gigantic theme park ride, except much scarier and with no known end," he wrote to CNN on Friday in an iReport from his home in Yabuki-machi, also in Fukushima Prefecture -- only about 180 kilometers, or 110 miles, from the center of the devastating 8.9-magnitude earthquake.
Payton, like many others, grabbed his phone or video camera and starting recording when the shaking didn't stop after a few minutes.
Ned Kubica, from California, was at a Tokyo hotel when it began. He went outside.
"There was glass broken from doors and windows from the next building over," Kubica told CNN in an iReport. "Everyone was in the street looking up at the buildings."
An American student living in Osaka told CNN that the "ground rolled for about two to three minutes and felt like waves of water washing over the house" when the earthquake rumbled through.
Afterward, "there was a strange, eerie creaking sound that emitted from the house and doors that were swaying from side to side. Outside, some of the poles and fixtures attached to houses moved but no buildings or houses were damaged," Brian Doyle, the student, said in an iReport.
In one area, a highway split neatly along the center dotted line, as if it were perforated paper. One half of the road ended up as high as 6 feet above the other. Residents peered down from the upper to the lower part of the road in disbelief.
Brent Kooi felt the quake as he was walking to the train station through a park in Chiba City, east of Tokyo, to go home.
"I thought I was dizzy or getting sick, then realized the earth was moving," he said in an iReport to CNN.
Video he shot showed sidewalk cracks expanding and shrinking as water bubbled up elsewhere in the otherwise peaceful park.
Erdrin Azemi says she was scheduled to fly out of Tokyo's Narita Airport on Friday, but the quake halted all travel. When the first earthquake hit, she and her fiance tried to get outside.
"We couldn't run because of the earth shaking. I started panicking because I thought the building might collapse," she told CNN.
Hours later, early Saturday, the couple was still inside the airport with hundreds of other stranded travelers.
"Everyone is calm. People are trying to rest," she said in an iReport. "There are small earthquakes every hour or so, sometimes more frequent. They last about 5-10 seconds. ... No one reacts to these quakes, we just look at the ceiling lights and point when we feel one."
Richard Dong was also at Narita Airport, in the Delta Air Lines Sky Club lounge.
"Soon after a small shaking, the whole lounge felt like (it was) jumping. Some parts from the ceiling fell off. Glass, cups, computers fell off from the tables," he recounted. "People started hiding under tables, staff working in the lounge kitchen ran out. A young mother tried very hard to push the door opening and let her kid out from the play room."
McDonald told CNN's Jim Clancy on Saturday that the shaking seemed to last forever.
"It got a little bit worse, so I went to the door to see how it was. ... It got considerably worse, and I said, 'This is the biggest one yet,' and then it didn't stop, so I went to stand outside between the two buildings.
"The clanking you hear (on the video he shot) is the canisters of natural gas banging against each other. That's when I said, 'Oh my God, the building is going to fall!' "
The structure of his building "had never made that sound. It sounded like a shotgun or a freight train going off, just BOOM!"
"That was absolutely the dumbest place for me to be standing (near the gas). At first I said, 'OK, I should get out,' ... (then,) when the cans started banging against each together violently, I saw lights in the alleyway -- I saw them physically just bounce into the air, about 3 feet into the air, and that's when I said the word that had to be beeped out" on the video he sent to iReport.
"Sorry," he added.
McDonald said his water, gas and phone services are out. He does have electricity, somehow. But all the grocery stores and shops near him are closed.
A shopper filmed the scene from inside a supermarket, showing employees desperately trying to keep merchandise on the shelves in the early moments of the powerful quake. They soon give up and scamper to safety as boxes and cans tumble to the ground around them.
"I don't know what I'm going to do tomorrow for food," McDonald said.
Armbrister is living with a host family in Ichihara in Chiba Prefecture. They'd just gotten through the initial quake and were suffering through the frequent aftershocks when they heard a loud "boom" in the distance.
"At that same moment, through the windows, we noticed the sky had instantly turned bright orange. We went outside and talked with the neighbors. Apparently, a plant of some sort had blown up," he explained to CNN in an iReport.
He grabbed his camera and went to get a closer look.
"The scene was wild. Cars stopped where they were to look at the chaos in the distance," Armbrister said. "I actually talked to a person who worked at the refinery. He spoke Japanese very fast, but he told me there were six explosions, and I understood one phrase he repeated -- 'the heat was unbearable.'
"The smoke was unbelievable. It completely blocked the blue sky. Night came quickly today," Armbrister said.
Then came the tsunami.
A sea of sludge and mud carrying wooden planks, trees, houses and cars oozed inland over Japan's eastern coast after the earthquake jolted the region and caused an unknown amount of death and destruction.
The wave moved slowly through the Honshu region, one of Japan's most populous. In some places, debris burned on top of the water -- flames sparked by heating oil tanks or gas lines that exploded in the shaking of the quake.
After the dirty water pushed through farmland, villages and cities, trees stripped bare of their leaves lay where they landed, their branches tangled with electrical wires, trash, insulation and foam mattresses; hulking, spiky giants jammed against crumbled buildings and walls of what used to be homes.
The scope of the devastation hasn't begun to emerge, as rescue crews try to make their way into the wide swath affected by the tsunami and earthquake.
Mark John Bennett, an American missionary in Narashino, in Chiba Prefecture, taped scenes of water outside his home, about half a mile from the beach of Tokyo Bay.
"The park across from us is flooding, it's from a tidal flood," Bennett said, narrating as he filmed water that seeped up from the ground and then went gushing down the street.
He tilted the camera upward during an aftershock, showing the telephone wires strung across the street dancing wildly from swaying telephone poles.
"Ah! Here we go! You see how we're moving, back and forth, like an island? Our entire block is moving, like it's an island!" Bennett said, as people around him yelped and shouted.
Amateur video recorded in Rikuzentakata, in Iwate Prefecture, showed a scene that could have been put together by Hollywood's best graphic artists.
The images show a small town, wrapped around a mountain-ringed bay, with fog rising off of the sea. You can't see the water move in. Instead, you see houses rise and gently ride the crest of the wave until they bump into other homes and buildings, moved by the unseen force of the tsunami and crushed by the weight of each other.
As far as 400 miles away from the epicenter of the earthquake, buildings in Tokyo shuddered and swayed.
American Zack Philipp serves in the Navy at Yokosuka city, in Kanagawa Prefecture. He was inside a bureaucratic office fixing his vehicle registration when the temblor struck.
"I first thought it was a small quake and that it would end soon. After 15 seconds, I realized this was much larger than what I had experienced before," he told CNN in an iReport.
He saw people running to the street and followed them. That's when he saw that the side of the building had fallen.
"I turned and started walking down the street when I saw the side of the building and how it had fallen. The scene around the building was like very calm, the search and rescue crews seemed to operate at a very calm, collected pace," Philipp said.
"It's kind of eerie, as there is not much talking. Most people are walking home in silence," he added.