As fire raged along the Southern California border this week, U.S. Border Patrol agents found themselves rescuing undocumented aliens who had given up, in some cases, even calling for help.

On Tuesday, agents rescued six Mexicans holed up in a World War II bunker on Otay Mountain in San Diego County.

"They called 911," said Border Patrol Agent Al Siapno of the San Diego Sector public information office.

In all, more than 200 undocumented aliens were arrested by Border Patrol agents since fires swept through the region Sunday. But the grisly discovery Thursday of four charred bodies – burned so badly officials still don't know if they're aliens or U.S. citizens -- makes it clear that not everyone was lucky enough to get out alive.

"With the size of the fires and the areas it covered, a lot of the common trails used by undocumented aliens were part of the fire, were in the middle of it, so it's not unlikely that we find more," Siapno said. "But we're hoping we don't."

More than 1,900 agents police the 60 miles of border fence and 91 miles of coastline in the San Diego Sector, one of the nation's largest crossings for undocumented workers. Last year, 142,000 were arrested; this year's latest figures, from August, stand at 141,047.

The fires temporarily strapped border operations, with 115 agents each shift being sent to help local authorities with evacuations.

"It did decrease some of our support on the line, on our border," Siapno said. "But also the fires were stopping a lot of the crossings in certain areas. It shortened our manpower but the bigger picture is a lot of people needed help."

And many of the agents found their own families being evacuated, so the agency set up shelters for Border Patrol employees and their families at two facilities – an option for those opting not to travel to Qualcomm Stadium. Some 60 horses, used to track smugglers and their cargo through the wilderness, were also evacuated.

The Harris Fire in particular threatened operations on the Mexican border. A facility near Tecate was evacuated and flames came within 10 feet of the 94 Checkpoint on Highway 94, but remarkably, only one vehicle was destroyed.

As the fires come under control, Border Patrol is almost back to business as usual, and for illegals as well.

"Now since the fires are pretty much gone from the border areas, they're not turning themselves in any more," Siapno said.