GUATEMALA CITY – A massive sinkhole that gulped down a clothing factory and an entire intersection in Guatemala’s capital is mystifying geologists who have yet to figure out what caused it.

“It’s the million-dollar question,” said David Monterroso, a geophysical engineer with the National Disaster Management Agency.

Nearly 100 feet deep and 66 feet wide, the hole formed during a deadly tropical storm in late May. Officials have not confirmed any fatalities, though neighbors say they believe a security guard using a public phone was sucked in and died.

One popular theory that has played widely in Guatemalan media is that flow from broken sewage ducts ate away at the earth until the ground above caved in. Another sinkhole that swallowed several homes and killed three people in the same area in 2007 was blamed on rain and an underground sewage leak.

But Monterroso said Thursday that not all the evidence is in.

“We could say the cavern formed because of leaky pipes, but it could also be true that when the cavern was forming, it created the fissures in the pipes.”

“It’s the chicken-and-egg question,” he said.

He said crews are waiting for needed equipment and will soon descend into the cavernous hole to investigate further.

Officials are still considering whether it can be filled, as a local cement company suggests, with a mix of cement and volcanic ash from the May 27 eruption at the nearby Pacaya volcano.

The government has evacuated everyone who lives and works near the sinkhole over fears it could widen, but officials say it’s unlikely any new holes will form.