There was one early report of possible looting, but no one was arrested, Swanton said.
He was now grieving for the potential loss of his colleagues, Mr. Swanton said.
Though there are no indications of criminal activity, Swanton said, it has not been ruled out yet.
"It has taken a toll on him because he knows he has lost some firefighters, " Mr. Swanton said.
However, lead researcher Prof Charles Swanton's tests on bowel cancer showed "very little evidence" that was the case.
Mr. Swanton said authorities didn't yet know if the fire and the subsequent explosion was an accident or intentionally set, according to the Associated Press.
William Patrick Swanton said, it has not been ruled out yet.
CNN: 12 bodies recovered, 60 unaccounted for after Texas blast
In the study, led by Marco Gerlinger and Charles Swanton at the London Research Institute, researchers obtained tumor tissue from four patients with kidney cancer.
Mr. Swanton, who was assisting West authorities, told reporters around 2:15 a.m. that the people unaccounted for included several firefighters and at least one law-enforcement officer.
Professor Swanton said as a clinician the findings did not surprise him but they helped explain why cancers are so difficult to treat once they have spread.
William Patrick Swanton said early Thursday morning that the death toll is only an estimate as search and rescue operations remain under way in the town of West.
Mr. Swanton described a scene of "extreme devastation" near the site of the explosion and added that he expected there would be a rising list of fatalities by morning.
Prof Swanton said the findings underlined the importance of early diagnosis of cancer before it had spread, and the need to target the common mutations in the 'trunk' of the cancer.
William Patrick Swanton told reporters.
CNN: Texan town tries to rebuild with community, spirituality
应用推荐