Port-au-Prince, Haiti (CNN) -- Teams of rescuers in Haiti's capital rushed to the city's Caribbean Market on Tuesday after a machine used to clear rubble caused a secondary collapse, trapping at least one Haitian in the rubble.
A French excavation team was working the site, which collapsed in the January 12 earthquake, said Lt. Col. Christophe Renou of French Civil Protection. The team spotted a body in the rubble and brought in an excavation machine, which resembles a bulldozer, to attempt to reach the body, he said.
The machine tipped into a hole, however, and caused further collapse, Renou said. Several Haitians were in the building at the time, he said, some helping in the search and others looking for useful items. Teams are aware of at least one person alive, confirmed with radar.
Renou said he believes more people are trapped, but he doesn't know how many or whether they are alive.
The French crews called U.S. and Mexican teams to the site to help with the rescue. The U.S. team brought more radar and lifting devices to try to extract the known survivor and reach any others, said Norman Skjelbreia, an incident commander from the U.S. Army Corps of Engineers.
The rescue mission is complicated, he said, by the Caribbean Market's debris and rubble and an adjacent building that is partially collapsed.
More than 212,000 people died in the earthquake, Haitian officials said, and bodies are being recovered every day.
Rescuers pulled an apparent survivor of the original quake, Evan Muncie, 28, from the rubble of a market on Monday. Doctors found him suffering from extreme dehydration and malnutrition, but without significant crushing injuries.
Muncie's family told staff at the hospital that he had been missing since the quake, and was found in the wreckage of a market where he sold rice. Muncie told doctors that someone brought him water while he waited for rescue, but sounded confused and sometimes thought he was still in the rubble.
By Wednesday, Muncie was in stable condition, according to University of Miami hospital spokeswoman Nery Ynclan, who said he was more alert and aware of his surroundings and was answering questions.
Ynclan said Muncie had eaten and even asked for chocolate -- which staff provided in small quantities. Muncie will be at the hospital at least another week, she said. His brother and mother arrived Monday at the hospital to be with him, she said.
Ynclan also said that crews returned Tuesday to the the site where Muncie was found and determined he may have been trapped in a room with some food or water. He was likely not pinned down, she said, but scrapes on his hands and feet indicate he may have tried to climb out.
CNN's Ingrid Formanek and Danielle Dellorto contributed to this report.