Warsaw, Poland, Safar 02, 1436, November 24, 2014, SPA -- A suspected arson fire in southwestern Poland has damaged a 750-year-old oak tree believed to be the country's oldest, AP reported. The deputy chief forest ranger in Szprotawa, Jerzy Wilanowski, said Monday that firefighters battled the blaze for more than 30 hours last week using water and foam. Foresters noticed the fire Tuesday morning. Wilanowski said that authorities will know in May whether the tree has survived, if it grows new shoots. He said he knows of a case of an old oak tree surviving a fire. "I was sure that the "grandpa" would survive me, but now I'm not so sure," Wilanowski told The Associated Press, referring to the tree in an affectionate way. "We have to wait." The tree is nicknamed "Chrobry" after a Polish medieval king. Its trunk circumference is more than 10 meters (33 feet) and it is more than 28 meters (92 feet) high. The oak is protected by law and an arsonist faces up to 10 years in prison if convicted. The police are investigating. Wilanowski said that a few branches were cut from the tree after the fire, to preserve its genetic material in case it does not survive and fresh acorns were put "with reverence" into pots, to grow. Oaks from Chrobry's earlier acorns grow in more than a dozen hectares of the forest. -- SPA 20:33 LOCAL TIME 17:33 GMT www.spa.gov.sa/w