The following is a compilation of documented eyewitness accounts of molten metal at the World Trade Center.
Reports from Direct Eyewitnesses
Leslie Robertson, structural engineer for the design of the World Trade Center
"[T]hey pulled out the big block of concrete and there was like a little river of steel flowing."
https://youtu.be/rjmHqES_lto?t=46s
Peter Tully, president of Tully Construction of Flushing, NY
Told AFP that he saw pools of "literally molten steel" at the World Trade Center.
Richard Riggs, debris removal specialist
Quoted in The History Channel's “World Trade Center: Rise and Fall of an American Icon”:
"The fires got very intense down there and actually melted beams where it was molten steel that was being dug up."
https://youtu.be/3Ogrupgt4mI?t=36s
Abolhassan Astaneh, professor of civil engineering at the University of California, Berkeley
One of the leading structural engineers who studied the collapse of the World Trade Center on 9/11:
"I saw melting of girders in World Trade Center."
Mark Loizeaux, founder of Controlled Demolition, Inc.
"There are both video tape and still photos of the molten steel being 'dipped' out by the buckets of excavators."
Capt. Philip Ruvolo, FDNY
"You get down below and you'd see molten steel—molten steel running down the channel rail, like you're in a foundry, like lava."
Joe O'Toole, firefighter
"Underground fires raged for months. O'Toole remembers in February seeing a crane lift a steel beam vertically from deep within the catacombs of Ground Zero. 'It was dripping from the molten steel,' he said."
http://911research.wtc7.net/cache/wtc/evidence/messengerinquirer_recoveryworker.html
Greg Fuchek, vice president of sales for LinksPoint, Inc.
"In the first few weeks, sometimes when a worker would pull a steel beam from the wreckage, the end of the beam would be dripping molten steel."
http://gcn.com/articles/2002/09/09/handheld-app-eased-recovery-tasks.aspx
Richard Garlock, a structural engineer for LERA
"Going below, it was smoky and really hot. . . . The debris past the columns was red-hot, molten, running."
http://www.pbs.org/americarebuilds/engineering/engineering_debris_06.html
James Glanz, writer for The New York Times
"A three-foot stalagmite of steel, which looks for all the world like a drip candle, sits next to one of the immense steel columns that held up the north face of the tower."
Lee Turner, paramedic
Turner himself crawled through an opening and down crumpled stairwells to the subway, five levels below ground. He remembers seeing in the darkness a distant, pinkish glow — molten metal dripping from a beam.
http://web.archive.org/web/20140106090807/http://www.usnews.com/usnews/9_11/articles/911memories.htm
William Langewiesche, journalist
"In the early days, the streams of molten metal that leaked from the hot cores and flowed down broken walls inside the foundation hole.”
http://www.amazon.com/exec/obidos/ASIN/0865476756/centerforcoop-20 (pp. 31-32)
Ron Burger, public health advisor at the CDC
"Feeling the heat, seeing the molten steel, the layers upon layers of ash, like lava, it reminded me of Mt. St. Helen's and the thousands who fled that disaster.”
http://www.brazoshealth.org/sites/all/themes/health/images/pdfs/messages_in_the_dust.pdf
Mike Donoho, interim Bryan Fire Department chief
"What you had were large columns of steel that were just stuck into massive amounts of molten steel and other metals."
http://web.archive.org/web/20021104073017/http://www.theeagle.com/septanniv/091102firefighter.htm
Tom Hickey, union ironworker
With no special protective gear, he worked within a few feet of still burning fires, [which were] "like a volcano," hot enough that molten steel could be seen dripping down. "My boots melted every night," he recalled. "You just didn't stand in one place too long."
http://www.riverreporter.com/issues/02-09-05/wtc.htm
David Long, Merrill Lynch
"I went outside and saw a large hole in the left-hand tower, approximately 80 stories up. There was smoke coming out, but not a lot of fire. I could also see streams of molten metal coming from undamaged areas of the building, in three different places."
http://www.abc.net.au/news/2011-09-09/eyewitness-accounts-of-september-11/2866958
Lee Turner, Boone County Firefighters
"He remembers seeing in the darkness a distant, pinkish glow— molten metal dripping from a beam—but found no signs of life."
Reports from Hearsay Witnesses
Ken Holden, NYC Department of Design and Construction Commissioner
Oversaw the organizing of demolition, excavation, and debris removal operations at Ground Zero, later told the 9/11 Commission:
"Underground, it was still so hot that molten metal dripped down the sides of the wall from [WTC] Building 6.”
http://www.historycommons.org/entity.jsp?entity=ken_holden
Alison Geyh, Ph.D., John Hopkins Bloomberg School of Public Health
"Fires are still actively burning and the smoke is very intense," reports Alison Geyh, Ph.D. "In some pockets now being uncovered, they are finding molten steel."
http://www.jhsph.edu/Publications/Special/Welch.htm
Herb Trimpe, chaplain
"I talked to many contractors and they said they actually saw molten metal trapped, beams had just totally had been melted because of the heat."
http://web.archive.org/web/20021006003613/http:/www.recordonline.com/adayinseptember/trimpe.htm
Kathy Dawkins, New York Department of Sanitation (DSNY) spokeswoman
"For about two and a half months after the attacks, in addition to its regular duties, DSNY played a major role in debris removal — everything from molten steel beams to human remains."
http://waste360.com/mag/waste_dday_ny_sanitation
Sarah Atlas, New Jersey Task Force One Urban Search and Rescue
"Fires burned and molten steel flowed in the pile of ruins still settling beneath her feet."
http://www.sas.upenn.edu/sasalum/newsltr/summer2002/k911.html
Ben Johnson, first responder
“The workers go through three pairs of rubber boots a day because they melt in the three-week-old fire of molten metal and jet fuel."
https://web.archive.org/web/20100225015212/http://www.illusiongenius.com/articles/11-01.html