Firefighters work at the scene of an explosion on East Lewelling Boulevard in Ashland, an unincorporated community near Hayward. A firefighter works at the scene of an explosion on East Lewelling Boulevard in Ashland, an unincorporated community near Hayward. Pacific Gas and Electric Co. said it had stopped the flow of gas to a home near Hayward that exploded about an hour later.   Crews from the Alameda County Fire Department and Pacific Gas and Electric Co. inspect the site of an explosion near Hayward.  The home at 867 E Lewelling Blvd in Ashland, an unincorporated community near Hayward, exploded when a construction crew struck a gas line Thursday. UPDATE: Agencies probe cause of Hayward gas explosion at county construction site Six people were injured and three buildings were destroyed in a residential explosion and fire Thursday morning near Hayward, hours after a construction crew hit an underground gas line, according to East Bay officials and Pacific Gas and Electric Co.  The Alameda County Fire Department responded around 9:38 a.m. to reports of an explosion and house on fire on the 800 block of East Lewelling Boulevard, located just south of Interstate 238 and north of Hayward, said Deputy Chief Ryan Nishimoto.  Advertisement Article continues below this ad Six people were transported to local hospitals, including some construction workers on the scene. Three people were taken to a hospital in “bad shape,” and two others reported minor injuries, fire officials said. Two people authorities said had been unaccounted for were found safe elsewhere.   A spokesperson for PG&E said the company was notified at 7:35 a.m. that a construction crew damaged an underground gas line while digging at the property on Lewelling. PG&E immediately dispatched crews to the scene, according to the company, and stopped the flow of gas at 9:25 a.m.  The explosion occurred roughly 10 minutes later, according to PG&E.  Advertisement Article continues below this ad “Those on site, including PG&E Crews worked with first responders on site to make the area safe,” the company said in a statement.  Multiple agencies have began investigations into Thursday’s explosion, including CAL/OSHA and the National Transportation Safety Board. Several agencies are investigating the explosion and fire in an unincorporated community near Hayward.       The property that exploded was at 867 E. Lewelling Blvd., in an unincorporated Alameda County community called Ashland. Zillow lists the property as a 3,957-square foot single-family home with four bedrooms and two baths built in 1950 and valued at more than $1 million. The neighborhood includes homes and small commercial buildings, including a State Farm Insurance office, a cannabis store and a real estate brokerage. The county is undertaking a major infrastructure improvement project on the stretch of road where the property exploded. Crews have been creating new sidewalks, adding bike lanes and rehabilitating pavement along East Lewelling Boulevard from Meekland Avenue to Langton Way, according to a county webpage. Advertisement Article continues below this ad The project manager, Amber Lo, did not immediately respond to a phone call seeking more information. The Oakland-based Redgwick Construction Co., which lists improvements at East Lewelling Boulevard on its projects page, did not immediately respond to a request for comment. Michelle Woods, who lives across the street from the site of the explosion, was unloading groceries around 9:30 a.m. when she heard a “giant boom,” she said. “Stuff was flying in the air. Everyone started running out of their homes, and then we saw the flames erupt,” she said. County construction crews had been working on the street for about a year and were working at the time of the explosion, said Woods, who described  emergency workers pulling construction workers from the area after the explosion. Nishimoto, the deputy fire chief, said about 75 firefighters were on the scene. Advertisement Article continues below this ad Firefighters, who arrived to smoke and flames shooting from the building, found a badly burned person on the street, fire spokesperson Cheryl said. Crews were working to stamp out the last remnants of the fire around noon, before completing a search of the two properties impacted by the incident.  Alameda County is undertaking a major infrastructure improvement project on the stretch of road near Hayward where the property exploded. Three buildings, including two residences and a workshop, suffered significant damage, Nishimoto said.  Around 2:30 p.m., several firefighters and PG&E workers remained at the scene, their boots crunching shards of glass from blown out windows. A passerby walking on the sidewalk tripped over a splintered beam barbed with nails that apparently flew across the street. The Alameda County Sheriff’s Office evacuated residents from nearby properties, said public information officer Sgt. Roberto Morales.  Advertisement Article continues below this ad “We’re continuously working together to try to make sure that everyone is safe,” he said. Ahead of the explosion, Christian Maldonado and his wife, Brittany, were at home when they noticed a PG&E worker appear at the side of their house, unannounced. When Brittany went outside, the worker said the crew was turning off the gas at nearby homes. About an hour later, they heard the boom. “My first thought was, ‘Chain reaction,’” said Christian Maldonado, adding that he and his family immediately left the house and went outside. “If they hadn’t shut off our gas, I don’t know what could have happened.” Maldonado said the building across the street had been a small apartment building with three units. He said he saw fire crews pull a man out of the building.  “He had all of his clothes burned to him,” Maldonado said. “You could see his skin where his shirt had been.” Around 4 p.m., Maldonado and his son were seated on lawn furniture at a neighbor’s driveway, waiting for crews to give the all clear to let them back inside.