The operator of a German industrial park that was rocked by an explosion on Tuesday dampened hopes of finding more survivors in the debris and warned residents near the site to stay away from soot that rained down after the blast.Two people were found dead after the explosion at the Chempark site, home to chemicals companies including Bayer (BAYGn.DE) and Lanxess (LXSG.DE), and 31 were injured.Five are still missing, Currenta chief Frank Hyldmar told journalists on Wednesday, adding that “we have to assume that we will not find them alive”.With the focus on the scene still on finding the missing people, including with the aid of high-resolution drones, the company said it was still too early to say what caused the explosion, which led to a fire in a tank containing solvents.Experts are also analysing whether soot that rained down on the surrounding area after the blast could be toxic.Until the results are in, residents should avoid getting the soot on their skin and bringing it into the house on their shoes, and they should not eat fruit from their gardens, Hermann Greven of the Leverkusen fire department said.He also said that playgrounds in the area have been closed.