OFD Rescue team working hard to extricate stuck worker #confinedspacerescue pic.twitter.com/PGVGz5lRvx — Oakland Firefighters (@OaklandFireLive) January 13, 2016

7.5 hrs later. @Cityofoakland till excavating trapped worker. Pit collapsed while replacing sewage line. pic.twitter.com/RQZguJyvZu — alan wang (@AlanWangABC7) January 13, 2016

Colleagues of trapped plumber watch rescue at 21st Ave. & E 23rd. 13 ft pit collapsed @CityofOakland pic.twitter.com/D9W5e3WaJH — alan wang (@AlanWangABC7) January 13, 2016

Worker trapped in 13 ft hole that collapsed while attaching sewer lateral to main line in @CityofOakland. pic.twitter.com/EreEnA9J1b — alan wang (@AlanWangABC7) January 13, 2016

Massive rescue operation of man trapped in an Oakland sewer! pic.twitter.com/0GLTzyB9Rm — carolyn tyler (@ctylerabc7) January 12, 2016

OAKLAND, Calif. (KGO) -- Fire crews in Oakland have spent over 10 hours trying to rescue a man trapped in a collapsed trench in East Oakland.Tuesday afternoon, an independent contractor was trying to replace and attach a sewer service line from a home to a main sewage pipe under the street when the trench collapsed on him. It happened around 12:30 p.m. on E. 23rd Street and 21st Avenue and the work was being done for the homeowner.The worker, who works for Star Rooter and Plumbing, had to go down 13 feet underground to work on the line. What was a 4x3-foot hole closed up to about a 2x3-foot space.According to a fire official, there was not sufficient cribbing -- plywood around the hole -- so dirt started caving in, burying him up to his chest. After hours of the rescue underway, the level of dirt trapping the man is now down to his knees.A friend identified the worker as 41-year-old Rogelio Esparza, who lives in Hayward. Esparza told his friend that he was buried alive.Heavy rescue teams are trying to shore up the trench so they can safely remove him. Fire crews said this would be a long process.Esparza has a harness on and is hooked up to an IV. Medical crews are keeping an eye on his vital signs as temperatures fall overnight, which could hamper his condition.They are concerned about his circulation due to all of the pressure that is squeezing his lower extremities.The soil has consistency of sand, which is making it very difficult to hold it back. That is why they are using a street cleaner to vacuum the dirt out of the trench while they dig. Esparza's foot is also trapped in a squishy clay, creating a suction force that is holding him down. That is a complication that has caused this rescue to drag on for so long.Rain moved into the Bay Area overnight so sand bags were brought in around 11 p.m. to try to keep any rainwater from flowing into the trench.