ZAMBOANGA CITY: A street sweeper foiled an attempt by a suspected arsonist to burn a public market in Zamboanga City, police said Thursday. Roman Francisco, a market sweeper said he spotted and chased a masked man who was pouring gasoline on one of the stalls. The masked man left plastic gallon containing gasoline which was taken by responding policemen for investigation. Last October 31, a huge fire hit the market site in downtown Zamboanga, killing 15 people and seriously injured five others who own stalls in the market. Mayor Beng Climaco has ordered a thorough investigation into the tragedy that left P8 million in properties up in smoke. She said an initial report pointed to a stall owned by a certain Mannan as the origin of the fire which quickly spread throughout the block in a busy area called Magay.