Updated at 10:30 p.m. Feb. 19, 2015

The San Diego Chargers and Oakland Raiders announced Thursday they are working on a plan to build a $1.7 billion football stadium to share in the Los Angeles County city of Carson if they are unable to strike deals for new facilities in their respective cities.

“We have both been working in our home markets to find a stadium solution for many years, so far unsuccessfully,” according to a joint statement issued by the teams. “We remain committed to continuing to work in our home markets throughout 2015 to try to find publicly acceptable solutions to the long-term stadium issue.

“… We are pursuing this stadium option in Carson for one straightforward reason: If we cannot find a permanent solution in our home markets, we have no alternative but to preserve other options to guarantee the future economic viability of our franchises.”

The teams are working with a business and labor coalition calling itself Carson2gether. The group plans to hold a news conference Friday in Carson to discuss the proposed stadium, which would be built at Del Amo Boulevard and the San Diego (405) Freeway.

According to the group, it plans to begin a petition drive to put the plan for a 72,000-seat stadium before voters.

On its website, the Los Angeles Times reported that the teams are planning a privately financed $1.7 billion stadium that would include 18,000 parking spaces with room for tailgating.

Mark Fabiani, the Chargers executive who has been spearheading efforts for a new stadium, could not be reached late today for comment. The city of San Diego has created a task force charged with finding a stadium site and developing a financing plan.

Adam Day, chairman of that task force, called news of the Carson proposal “a complete surprise.”

“… While it’s disappointing to hear the Chargers are moving forward with plans in Los Angeles, we remain committed to finding a solution in San Diego,” Day said. “We’re working toward selecting a site and developing a financing plan for a stadium, and we’re going to stay focused on that.”

San Diego Mayor Kevin Faulconer also expressed disappointment, saying in a statement, “It’s now abundantly clear that while we have been working here in San Diego to create a plan for a new stadium, the Chargers have for some time been making their own plans for moving to Los Angeles. This would amount to abandoning generations of loyal Chargers fans. Despite this news, we are going to continue our efforts to develop a viable stadium solution.”

The Times reported that the teams have already purchased the 168-acre plot of land in Carson from Starwood Capital Group.

Architect David Manica, who is working with the teams on the Carson proposal, told The Times the facility would be “a 21st Century, next- generation stadium.”

“We want it to be the ultimate outdoor event experience, which includes both sports and entertainment,” Manica told The Times. “And we want it to be uniquely L.A.”

Manica, while working for HOK Sport, led the design of the Texans’ stadium in Houston and the renovation of the Miami Dolphins’ stadium.

News of the proposal comes about a month after St. Louis Rams owner Stan Kroenke joined with the developers of the former Hollywood Park site in Inglewood to announce plans for an 80,000-seat stadium at the location.

The Rams are also pushing for a new stadium in St. Louis.

The Hollywood Park developers have already collected enough signatures to have the stadium issue placed on the city ballot. The Inglewood City Council is expected to certify the signatures during its meeting on Tuesday.

The city of Los Angeles, meanwhile, has an agreement in place with the Anschutz Entertainment Group for a possible NFL stadium adjacent to the Convention Center in downtown Los Angeles. That deal is contingent on an NFL team agreeing to relocate to the facility.

Developer Ed Roski has also been pushing a stadium proposal in Industry.

An NFL team has not played in the Los Angeles area since 1994.

The Los Angeles Raiders played at Los Angeles Memorial Coliseum from 1982-1994, before returning to Oakland in 1995. The Los Angeles Rams played in the Coliseum from 1946-1979 and at what was then known as Anaheim Stadium from 1980-1994 before moving to St. Louis in 1995.

The Chargers played at the Coliseum in their inaugural 1960 season when they were a member of the American Football League, then moved to San Diego in 1961.

— City News Service

Chris Jennewein is founder and senior editor of Times of San Diego.