Investigators worked overnight to reach the ruptured gas line in south Minneapolis that became the scene of a major natural-gas fueled fire on Thursday.
Workers had to pump water out of the hole in the street to reach the line, state Office of Pipeline Safety spokeswoman Kristine Chapin said.
Chapin said the hole was up to 5 feet deep.
"There's water running into it, because as you can imagine, with the snow melting the ground is saturated," Chapin said.
No one was injured Thursday morning when the ruptured gas line caught fire, but the incident forced the temporary shutdown of Interstate 35W and parts of Highway 62. Several city streets were also blocked as firefighters responded. The blaze was so hot it melted tires and headlights on cars parked in the nearby Cub Foods parking lot.
Eyewitnesses said they heard an explosion, but investigators are not calling it that.
"People who work in the pipeline industry ... use the words 'fire' and 'explosion' separately and distinctly. The media was using the word 'explosion' yesterday, and in fact that's not what happened there," she said.
Chapin said just because people heard something that sounded like an explosion, that doesn't mean anything technically exploded.
"When a pipe leaks and the gas starts on fire under 175 lbs per square inch of pressure, you're going to have a large, immediate event, which is not really an explosion," Chapin said. "When you turn on your gas stove, the gas is coming out and the gas is on fire. That's what was going on yesterday but it was enormous and it was horrible."
Chapin said after looking at the pipe, CenterPoint Energy will do temporary repairs.
CenterPoint spokeswoman Becca Virden said investigators expect to remove the pipe by the end of Friday or sometime Saturday.
"We will take that segment and maintain custody of it," she said. "Then they will conduct their investigation and we will work very closely with the Office of Pipeline Safety."
Virden said it's unclear how long the investigation could take.
(MPR reporter Jess Mador contributed to this report.)