Portland Fire & Rescue along with the Bureau of Alcohol, Tobacco, Firearms and Explosives opened a tip and information line for Sunday’s five-alarm fire at the Thunderbird on the River.Anyone with tips, information, videos or photographs of the fire is asked to call 1-800-800-3855.To speak with an agent, select Option 2 at the first voice prompt and then Option 3 at the second prompt. Callers may remain anonymous, but contact info is needed for follow-up calls. “It is important in large-scale fire investigations to enlist the public’s help in providing possible leads,” said Christopher Porreca, spokesman for the ATF. “Fire scenes are extremely complex and even the smallest bit of information could be crucial in identifying and assisting in the determination of the cause of the fire.”The fire sparked early Sunday morning at the vacant hotel at 1401 N. Hayden Island Drive. Firefighters estimate damage to be $5 million, if not more, based on damage to 85 percent of the six-building hotel.Meanwhile, David Austin, communications director for Multnomah County, confirmed on Wednesday that Thunderbird hotel owner Howard Dietrich owes $1.121 million in back taxes since 2008. He bought the hotel along with the Red Lion Hotel on the River-Jantzen Beach, on the east side of Interstate 5, for $28 million in 2005.At one point, Walmart was reportedly eyeing the site.