Updated at: 03/31/2014 3:57 PM
(AP) NEW YORK - NEW YORK (AP) â€” Federal investigators are moving to a lab in Washington to examine damaged gas and water mains from the scene of an explosion that leveled two Manhattan buildings and killed eight people.
The National Transportation Safety Board said Monday it has completed its work at the scene of the March 12 blast in East Harlem.
"We've been collecting facts on site, and now we'll continue in the lab," spokesman Eric Weiss said. "Then we'll begin analyzing and come to a probable cause and perhaps some recommendations."
He said it would be months before a cause is determined.
The NTSB said sections of pipe, including parts of a leaky gas main and a cracked water main found beneath Park Avenue near the buildings, are being shipped to Washington.
The agency reported March 18 that it had found a leak in the cast iron gas main, which was installed in 1887. It now says there was more than one leak. City officials said the blast erupted about 15 minutes after someone reported smelling gas.
Also going to the lab are a newer, plastic section of the main and parts of the pipes leading from the main to the two buildings.
The NTSB has said it was unclear if the broken water main, which dates back to 1897, contributed to the explosion or was caused by it.
Weiss said videos from camera probes into the gas and water mains were inconclusive.
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