Fear of an arsenic cloud prompted authorities to evacuate several hundred homes in southern Albert Lea late Saturday. The residents were allowed to return to their homes early Sunday.

“There was no actual spill or release,” said Albert Lea Police Chief Dwaine Winkels.

Freeborn County Sheriff Mark Harig said a semi with a double trailer caught fire at about 10:22 p.m. on Interstate 35 about a half mile south of Exit 8.

He said the driver thought he had brake problems and pulled over. The hitch was hot and he suspected a fire in the rear trailer. Albert Lea area firefighters and a hazardous material crews arrived, opened the trailer and gained control of the fire. Harig said the cause remains undetermined. The driver, he said, was not injured.

I-35 was shut down right away, and evacuation began.

Albert Lea Police Department, Freeborn County Sheriff’s Office, Austin Police Department and Mower County Sheriff’s Office assisted in the evacuation. Off-duty Albert Lea officers also were called in to help. People were sent to Albert Lea City Arena.

Harig said the rear trailer was carrying ammunition and some firearms and authorities feared it would explode and catch the other trailer on fire. That other trailer had the chemical arsenic in it. Arsenic is often used in the preservation of wood, but it is a powerful poison, too, prompting the evacuation. The wind in Albert Lea on Saturday night was about 7 mph out of the southwest, according to the National Weather Service.

“Had there been a vapor cloud, we didn’t want that to blow over the homes,” Harig said.

Lt. J.D. Carlson of the Albert Lea Police Department said homes south of South Shore Drive and east of South Margaretha Avenue were evacuated, along with homes on those streets and on Larson Avenue. Harig estimated “a couple 300 homes.” Officers were posted to keep people out of those areas. The most dense population was the South Margaretha neighborhood.

The all-clear message came only minutes after 1 a.m. Residents were allowed to return home. Northbound I-35 was open again. Southbound I-35 reopened at 2 a.m. The crowd at City Arena quickly dispersed.

A special hazardous materials team came to the trailer from Mankato, Harig said.

An early Salvation Army estimate of the people at City Arena had 133 people, but Carlson said that grew to 270. Others flocked to the hotels.

Many gathered at the parking lot for Albert Lea Medical Center’s Health Reach at the corner of Southeast Broadway Avenue and Margaretha Avenue. A school bus shuttled them to the City Arena.

The Salvation Army and the American Red Cross converged on the City Arena to assist people. Mayor Mike Murtaugh was there along with City Arena Manager Bob Furland and employees Phil Hensche and Troy Hagen. Henche and Hagen had been cleaning the City Arena following the Ducks Unlimited banquet on Saturday when the call from police came to open the facility to the evacuees. Albert Lea police and several volunteers were ready to help.

Capt. Jim Brickson of the Salvation Army said his crew was getting prepared to feed people snacks and, if necessary, breakfast. Meanwhile, the Red Cross volunteers were setting up cots. However good the intentions were, it seemed short-lived. The 1 o’clock release to return home seemed sooner than anyone had expected. Still, people were happy it was over.

Gabby Hernandez sat at a table with her husband, Victor. Their son, 2-year-old Carlos, slept on the table. They live in the New Hills Condominiums trailer court.

She said they heard a loudspeaker on a police car telling people in English and Spanish to evacuate to City Arena. They were getting ready to go when the New Hills manager knocked on the door.

Karen O’Bryne lives on Broadway Avenue and happened to be listening to the police scanner when suddenly there was a lot of radio traffic. Then she heard a police officer knock on the door.

“I don’t usually have anybody at the front door,” she said. “They said, ‘Arsenic! Dangerous!’”

Mary Lahs and Shirley Stundahl live in the New Hills, too, and they were worried about their pets. Lahs has two cats and Stundahl has three. At the time, people had the impression an arsenic cloud actually existed.

Dale Anderson lives on South Shore Drive only three houses from the freeway overpass. He said police parked in the driveway, rang the doorbell and knocked on the door with a flashlight. He and his mom got in the van and waited at the City Arena parking lot.

“They said it was a chemical leak on the freeway,” he said.

However, there was no leak. Hazmat workers were still unloading ammunition and other items from the truck at 3 a.m.