Some evacuees from Los Angeles-area warehouse fire return

Los Angeles County Firefighters stand on top of a roof and watch as an explosion erupts from a factory in Maywood, Calif. on Tuesday, June 14, 2016. Explosions rocked a small Los Angeles County city early Tuesday as an inferno raged through a business containing metals and and firefighters decided to allow the blaze to burn itself out.

MAYWOOD, Calif. (AP) — Some of the estimated 300 people forced from their homes by an explosive warehouse fire in Southern California have been allowed to return but others may have to wait until the weekend, authorities said Thursday.

About half of those evacuated during Tuesday’s blaze have returned, Los Angeles County sheriff’s Lt. Alex Salinas told City News Service.

They went home Tuesday evening but people living in homes that back up against the warehouse can’t return until testing ensures there is no health risk from ash and dust produced by the blaze, county fire Inspector Gustavo Medina said.

Tests for lead, magnesium and other metals were underway Thursday.

“We’re hoping that residents are going to return sometime Saturday,” he said.

The fire in this city of 28,000 south of downtown Los Angeles destroyed two commercial buildings, including a metal-recycling plant containing 10,000 pounds of magnesium shavings.

The magnesium erupted in fireball-like explosions when firefighters poured water on the flames. Fire crews declared the fire out Wednesday.

Investigations were underway into the cause of the fire and whether the business met all the extensive regulations for hazardous materials.