Here's who is on strike in LA, and what it means for Angelenos

The city of Los Angeles is on strike. A growing number of unions seeking improved conditions for their employees are halting movie productions in the city, holding up hotel business, potentially disrupting supply chains, and slowing down the airport.

Today, 11,000 Los Angeles city workers are joining Hollywood actors, among others on the picket lines, according to the union that represents many of the city's public sector staff. The strike is the first by LA city workers in more than 40 years.

The effects are city-wide: sanitation workers, lifeguards, custodians at public schools, LAX airport shuttle drivers and mechanics, crane operators and boat captains at the city's ports are among the workers who are planning to strike - or who have already walked off the job.

The heatwave and seriously short staffing - there are hundreds of job vacancies in the city - are causing union members to be "at their breaking point," David Green, president of SEIU Local 721, told CNN.

SEIU 721 is the union representing more than 95,000 workers in Southern California. Members voted to authorize the strike only after "repeated labor law violations" by Los Angeles city management, according to the union.

Usually, a lot of what their members do "goes unnoticed," said Green. "But on Tuesday, we're going to make sure everybody notices."

It comes amid a wave of union activity in the city and across the country.