UPDATED at 7:35 p.m.: The historic Civic Stadium in Eugene is considered a complete loss after a fire engulfed it Monday, sending flames shooting high into the evening air.

Flames rose to twice the height of the stadium, and 38 emergency units responded to the two-alarm fire, Eugene police said.

Authorities responded to the fire at about 5:26 p.m. and evacuated a two-block radius. The fire was under control about two hours later, police said.

"It appears as though the stadium is a total loss," Eugene-Springfield Fire Chief Randy Groves said in a video posted by The Register-Guard. The fire moved fast, he said, feeding on the dry stadium lumber.

The cause of the fire is under investigation, he said. Authorities reported no injuries.

Nearby structures were at risk, police said, and authorities were checking to ensure the safety of the area before allowing residents to go back into their homes.

The Register-Guard reported that the grandstands and the rest of the stadium were in flames Monday afternoon. Dozens of firefighters were attacking the blaze.

Smoke from the fire was visible throughout the Willamette Valley city.

Civic Stadium is a historic baseball park that was recently home to the Eugene Emeralds minor-league baseball team. The Emeralds have played at PK Park since 2010, according to their website.

Until recently, Civic Stadium had been owned by the Eugene School District. But the school district sold it for $4.5 million in a complicated deal involving the city and a nonprofit looking to renovate the stadium, The Register-Guard reported in April.

The Eugene Civic Alliance had dreams of turning the old stadium into a soccer field with basketball and volleyball facilities for kids.

In a statement posted online Monday night, the group said it was "stunned." The structure was insured and construction was scheduled to begin in July. The group, headed by attorney Derek Johnson, said that as far as they know, no volunteers or contractors visited the site Monday.

"It is too early for us to know where we go from here," the statement read. "We ask for a bit of grace and patience as we come to grips with this loss to our community and to our effort."

Photos of the fire have been posted to social media.

#BREAKING: Confirmed, Civic Stadium is on fire in Eugene. pic.twitter.com/HYn8woU6yx — Ty Steele (@KCRATySteele) June 30, 2015

Eugene, Oregon civic stadium on fire. pic.twitter.com/h3i5NoIokM — Francesco Somaini (@SomainiF) June 30, 2015

That's a lot of my childhood memories that just burnt down #CivicStadium — zo-wheezy (@Zobo420) June 30, 2015

Many good Civic stories, but my favorite will always be @CAnderson1954's recounting of the last time the Ems had 10-cent beer night. Chaos. — Andrew Greif (@AndrewGreif) June 30, 2015

This story will continue to be updated.

-- Jim Ryan

-- The Oregonian/OregonLive

-- Brad Schmidt

-- The Associated Press contributed to this report.