There were no reports of injuries or of any homes being damaged early Thursday.
Investigators with the Texas Railroad Commission were checking pipelines in the area and trying to determine if any regulations have been violated, said agency spokeswoman Ramona Nye.
Officials with Texas Natural Resources and Conservation were monitoring air and water quality. So far, no pollutants have been detected.
"Right now we're not concerned about any kind of explosion or any kind of hazard," said Tom Branch, coordinator of the Liberty County Office of Emergency Management. "We are monitoring some other things around the area to make sure everyone's OK."
Power provider Entergy cut electric lines Wednesday to prevent power from being cut off in the town.
Sunoco, which manufactures petroleum and petrochemical products, secured two 6-inch crude oil pipelines near the sinkhole that had started to leak Wednesday, said Lester Edwards, hazardous materials coordinator for Liberty County.
Television news footage showed a tractor, some oil field equipment and some telephone poles falling into the sinkhole as it grew near Daisetta, which has a population of around 1,000 and is located about 60 miles northeast of Houston.
The sinkhole was believed to have grown to at least 600 feet long and 200 feet deep by Wednesday night.
Farm-to-Market Road 770 was closed to traffic and vehicles were being diverted to FM 834 over concerns the pit could spread to the roadway.
Officials are trying to determine what prompted the sinkhole near the Liberty County community. But its history as a once booming oil town might be to blame.
The ground might have caved in because of the collapse of an old salt dome where oil brine and natural gas are stored underground, officials said. Daisetta sits on a salt dome, one of the most common types of traps for oil.
Sinkholes are rare and often take up to two weeks to stabilize, said Geoffrey Paine, a geologist and geophysicist with the University of Texas.