The fire from an LPG pipeline explosion that triggered the evacuation of the town of Milford on Thursday is expected to burn well into Friday, Ellis County officials said.

Officials said crews were excavating at the site at about 9:30 a.m. when a 10-inch liquid petroleum gas pipeline was punctured. Chevron, which owns the line, immediately evacuated its crew of five, who all escaped without injury. When the line exploded and caught fire, several vehicles and equipment parked at the site along Cosby Road were destroyed and burned.

The explosion was so strong that students felt it rattle school buildings approximately one mile away.

"We were in the weight room, coming out, when we heard a big explosion," said Geraldo Yanez, an eighth-grader in the Milford Independent School District. "Then we started seeing smoke."

"You could see the fire and then all the black smoke in the sky," senior Aryan Jordan said. "It was kind of close to the school -- very close."

Chevron said in a statement at about 2:30 p.m. that the flow of product along that particular pipeline in the West Texas LPG system had been shut off, though the residual burn off continues. Officials said Thursday afternoon that it may take up to 36 hours for the line to burn out and to cap the line.

By 4:30 p.m., seven hours after the explosion, the height of the flames coming from the pipeline was significantly reduced.

But officials warn that a real threat exists and said they are watching a 14-inch pipeline near the pipeline that ruptured. There is concern that if the line gets too hot from the nearby fire, it may explode, too.

Earlier in the day, firefighters from neighboring cities were called in to assist battling the fire, but officials decided it was safer to simply cut the supply of gas and let the contained fire burn out. There are no structures nearby that were either threatened or damaged by the explosion and fire.

Schools, Town Evacuated

Within 15 minutes of the explosion, roughly 200 Milford ISD students were evacuated as a precaution and taken to the high school in nearby Italy, where they were released to their parents.

"A lot of them were crying, asking questions, just wanting to know what was going on," said Konnecha Houston, a Milford ISD staff member.

The school district has canceled classes for Friday, and a playoff game scheduled for Friday night for the school's district champion, six-man football team remains up in the air.

Ellis County Sheriff's Lt. James Saulter said the town's 800 residents were also evacuated. He did not know as of Thursday afternoon how long the evacuation order would remain in effect. The Red Cross said it expects to house about 150 evacuees at Italy High School's Dome overnight.

County officials said the area has been roadblocked and that law enforcement would remain to keep the area secure. Residents will not be escorted to homes, even for medicine.

Road Closures

The Texas Department of Transportation is detouring traffic to Interstate 35E and closing several roads in the area. Drivers are urged to find alternative routes and to plan for delays. The following roads are closed:

Farm-to-Market Road 308 in Milford: Closed from state Highway 22 in Hill County to U.S. 77 in Ellis County.

U.S. 77 in Milford: Closed in the immediate area of the explosion.

Interstate 35E exit ramps to Milford are closed.

Farm-to-Market Road Road 566: Closed from I-35E to U.S. 77 in Milford.

Shortly after the blast was reported, Chopper 5 was dispatched to the scene. Once airborne, a massive plume of smoke was visible stretching across the horizon from about 40 miles away. From 20 miles away, flames shooting into the air were clearly visible, according to Chopper 5 photojournalist Ames Meyer.

The Texas Railroad Commission said an inspector has been dispatched to the area, but that the pipeline is a federally regulated interstate pipeline. It falls under the jurisdiction of the Pipeline & Hazardous Materials Safety Administration, which sent representatives to the scene.

Emergency response personnel with the Environmental Protection Agency are assisting with the response efforts to determine environmental effects of the explosion and provide additional support as requested. Additionally, the Texas Commission on Environmental Quality is monitoring air quality.

The Ellis County Fire Marshal's Office said it was not aware of any previous incidents at the site.

Since 2006, the Chevron Pipeline Company has reported 55 hazardous liquid pipeline incidents to the PHMSA that resulted in more than $108 million in property damage. However, they have had no reported injuries or deaths in that time period. According to the PHMSA, Chevron has 1,955 miles of pipeline across dozens of counties in Texas.

Pipeline Tracker

Pipelines such as the one in Ellis County can be found all over Texas.

You can take a closer look at the pipelines in your area on the Railroad Commission's website. The interactive map includes information and location coordinates for oil wells, gas wells and pipelines.

To see pipelines on the map, click on the "Visibility tab" on the upper-left-hand corner and select "Pipelines."

More information on map and the data can be found on the Railroad Commission's website.

Milford is a small town along Interstate 35E, northeast of Hillsboro in southern Ellis County. It is about 50 miles south of Dallas.

NBC 5's Ray Villeda, Randy McIlwain, Amanda Guerra, Shane Allen and Eva Parks contributed to this report.