Hidden tunnels are unearthed in a San Diego neighborhood. Who built them and where do they lead?

SAN DIEGO (CBS 8) - It had been an "urban myth" to some, the whereabouts of some hidden tunnels under San Diego.

Well, that myth is now reality after CBS News 8's Gene Kang went along with a group of people who made quite the underground discovery.

Tootie Thomas, President of the El Cajon Boulevard Business Improvement Association, gave CBS News 8 a tour of the tunnel and a history lesson in the process.

Gene: "It's not on your timeline. People don't know about it."

Tootie: "Yes we didn't know, we'd heard about it for very long. It was like an urban legend."

Tootie grabs her ladder while dressed in colorful clothing complete with spelunking boots, walking just feet away from her office near Wilson Middle School.

She places the ladder in a hole, surrounded by orange cones and barricades just across the street.

One-by-one, the team goes deep underground near the 3700 block of El Cajon Boulevard where there's a system of tunnels built in the 1930's.

Seven people in the group, including CBS News 8's photographer Scott Kavieff, unearth a tunnel at least 7-feet high, estimated to be more than 50 to 100 feet long. The tunnel is complete with cement, light fixtures and a walkway.

One end has drainage pipes through the wall and an old rusty gate blocking the entrance.

"There's a hollow room back there, but you can see the concrete poured in from up above," one group member said.

Kavieff used his camera light to illuminate the darkness as the ruins are explored. The opposite end of the tunnel looks like something out of a scary movie with part of a decades-old grocery cart on the ground and another gate covering what could be an exit to Wilson Middle School.

Tootie and her staff made this grand discovery weeks ago after doing their research. The crew learned there are three other tunnels in San Diego.

"We think it reached underneath the sidewalk and that was the access to the school," Tootie said.

A map presented to CBS News 8 shows the elaborate system and a discovered bond measure shows the City of San Diego paid $300,000 for various projects, including building four pedestrian tunnels in December 1931.

The pedestrian tunnels show one at El Cajon and 38th Street, another at El Cajon and Chamoune Avenue and two others. In that era, cars were just starting to become popular and above ground crosswalks weren't widely used.

The tunnels were created so students and others could walk to work or school safely. The team uncovered writing on the walls as well, including one woman who wrote her name and the year "1972", most likely the same year the tunnels were closed.

The tunnels were discovered this year by city crews who were working on a roadway median as part of a project to beautify the area. During their work, the crews detected a sinkhole that prompted a search leading to the discovery of the tunnels.

After almost two hours in the dark and dusty tunnel the crew needed some fresh air. They climbed their way back to the surface and made it safely across the street with a newfound appreciation for San Diego's living history.

UPDATE TO THE STORY...

After working on this report - Gene found someone who used these pedestrian tunnels as a student back in the 1960's - one of his co-workers!

Moana Pitcher, a long-time CBS 8 employee, used the pedestrian tunnel to get home safely from school.

She shared her memory of what it was like to travel underground.

"I used to take the bus to school but walking home meant going underneath Park Boulevard in the tunnel. There were steps down. On a hot day it was cool," Moana reminisced.