As Los Angeles begins the daunting task of rebuilding after some of the most destructive wildfires in its history, a critical workforce is at risk: undocumented immigrants who often take on the hard, dangerous jobs of clearing debris and constructing new homes.

Take Cesar, a Mexican immigrant in his 60s who has worked in construction around LA for over three decades. Like many others, he’s undocumented. Now, with the threat of mass deportations under a potential second Trump administration, workers like Cesar could be forced out, leaving a massive gap in the labor force needed to rebuild more than 12,000 damaged structures.

Builders in LA say recovery will already be slow due to permits, insurance delays, and the city’s notoriously high housing costs. Losing immigrant workers—who make up a significant portion of the construction workforce—could make it even harder. In California, 52% of construction workers are foreign-born, with nearly a quarter estimated to be undocumented.

Victor Narro of the UCLA Labor Center calls these workers “second responders.” They’ve helped build LA, and now they’re ready to restore it. But if deportations surge, the city could face a labor crisis. “Who is going to do the work of this large immigrant workforce?” Narro asks.

Trump’s tough stance on immigration, including threats to cut federal funding for sanctuary cities like LA, adds to the uncertainty. While the city has pledged to protect immigrant communities, federal actions could disrupt recovery efforts.

With thousands of jobs already unfilled in the construction sector, replacing undocumented workers isn’t as simple as hiring locals. “Building a house is strenuous work,” says Cameron Irwin, a local homebuilder. “Undocumented workers fill that gap.”

For Cesar, the stakes are personal. “California’s economy owes a lot to immigrants,” he says. “Mass deportations would hurt more than just us—they’d hurt the entire state.” As LA faces the long road to recovery, the fate of its immigrant workforce could determine how quickly the city rises from the ashes.