The "Sutro Social and Cards in the Cavern" event was held today to celebrate the grand opening of the Sutro Tunnel's expansion in Dayton.

When the project first began, the tunnel was completely collapsed with no way to get inside.

"And I'm like, well, why don't we clear that collapse and get into the tunnels," said Chris Pattison, Volunteer and previous Executive Director of the project. "Our board thought it was possible, but most people didn't. And because of our great board and events like this, and volunteers and donors, we've been able to raise the funds to have people come out and rebuild the tunnel based on historic documents."

While the tunnel has just finished being expanded, we've been told that another expansion is planned for October.

To visit the tunnel yourself, you can check for available tour dates on the Sutro Tunnel's website.