A hotel and apartment complex under construction in downtown St. Paul was severely damaged in a fire early Tuesday morning that could be seen for miles.

But the developer said he will restart the project. “Our intent is to continue,” said developer Carl Kaeding, president of Bloomington-based Kaeding Development Group.

No one was hurt in the blaze that was shooting high into the air when firefighters were called to the scene at W. 7th Street and Kellogg Boulevard about 4:20 a.m., said St. Paul Deputy Fire Chief Roy Mokosso.

Investigators from the St. Paul Fire Department, St. Paul police and the state fire marshal were on the scene well into Tuesday afternoon, but had yet to pinpoint the fire’s origin or cause, Mokosso said. They planned to sift through the debris and study video from nearby surveillance cameras to determine a cause.

The $69 million Seven Corners Gateway project across from the Xcel Energy Center, including a five-story 120-room Courtyard by Marriott hotel and a six-story building with 144 market-rate apartments, was on track to be completed by March.

The hotel was fully framed and windows had been installed before the fire, which caused part of the building to collapse. Brick work was to begin in the coming weeks, bringing 50 to 60 jobs to the work site, Kaeding said.

“It was devastating to hear,” he said. “Now that is delayed, too. It was a rough day.”

The damage was mostly confined to the hotel. Work on the neighboring apartment building, left standing and almost unscathed by the fire, will resume once authorities grant permission.

“That was a silver lining,” Kaeding said, praising firefighters who kept damage limited to the hotel.

The structure was “heavily involved” when fire crews arrived. They were forced to fight the blaze from the outside because of the flames and heat, Mokosso said.

“It advanced rapidly,” he said, partly because the unoccupied building had exposed drywall and wood that allowed the fire to grow quickly.

Firefighters went onto the roofs of nearby buildings to check for embers, including the Catholic Charities Dorothy Day Place campus, according to dispatch audio. Windows of a nearby building on W. Old 6th Street were reported to have cracked from the intensity of heat caused by the fire.

William Mujica of St. Paul woke up around 4:25 a.m. and saw the large fire “turned into flying flames,” he said. “Honestly, I felt the heat from about a mile out.”

By 6:30 a.m., crews had put out most of the fire and were concentrating on dousing hot spots, Mokosso said. Debris littered several streets, and roads in the area of the fire were blocked off.

Ramps from eastbound Interstate 94 to 5th Street and northbound Interstate 35E to Kellogg Boulevard were closed for about two hours but have since reopened, according to the Minnesota Department of Transportation.

“It’s incredibly sad to see all the construction teams’ hard work get leveled so quickly,” Kaeding said

Catholic Charities officials said they were assessing damage to their buildings.

“We are so grateful to the St. Paul Fire Department for their quick work early this morning keeping our residents and guests safe,” said Wendy Underwood, a Catholic Charities vice president.

Doran Cos., the general contractor, issued a statement saying that they were “reeling. We are pretty devastated by this.”