Hundreds of Monument residents had to flee their homes for about 15 hours, schools were closed and traffic detoured Wednesday because of the threat from a train tanker leaking hydrochloric acid.

Residents of all but 12 of the 250 homes evacuated were allowed to return at 8:30 p.m. Wednesday. The final few evacuees  were allowed back in by 10 p.m. after most of the acid had been transferred to another tank car.

“We’ve had a lot of success with this situation,” Monument Police Lt. Steve Burk said as the evacuation  was lifted. “Everything has gone flawlessly.”

The drama began about 1 a.m. when the crew of another train spotted a vapor cloud around a tanker car of a northbound train stopped on a siding just south of Monument and west of Interstate 25. Once the spill was identified, reverse 911 calls were made to 250 homes in the Santa Fe Trail subdvision beginning about 4:30 a.m. because of the threat of a toxic acid cloud.

School was canceled in Lewis-Palmer School District 38 and a evacuation center was set up in the former Grace Best Elementary School. School’s are scheduled to be open today.

Police officers, sheriff’s deputies, firefighters, health department officials and hazardous materials crews descended on the scene to test the air, evaluate the danger to the community and clean up the mess.

A Burlington Northern Santa Fe Railway hazaroudous material crew was flown in from Texas and Arkansas to transfer the acid to another tanker, a task that began about 4:15 p.m.

By 8:30 p.m., the acid in the car was below the leak, so most evacuees were allowed to go home. Residents of 12 properties that abut train tracks had to wait another 90 minutes.

“It’s a very critical time when you transfer that chemical,” El Paso County sheriff’s spokesman Sgt. Mike Schaller said.

The leak's impact was already widespread, though, as 25 trains were delayed due to the ordeal.

See a map of the evacuation area here.

Inhaling hydrochloric acid can result in coughing, chest pain and a sore throat, said Kandi Buckland, head of the county’s health department. More intense exposure can cause burning of the respiratory tract, coughing up blood, shortness of breath and fluid building up in the lungs.

No serious injuries were reported.

“I think everything is well under control,” Buckland said Wednesday afternoon. “It doesn’t appear we have any lingering health effects.”

Hazmat crews stopped the leak around noon by affixing a magnetic patch to the tanker. The temporary fix held until the arrival around 2 p.m. of the railway crew from Fort Worth.

 About a cup per minute of the acid leaked from the tanker, which holds more than 20,000 gallons. Sheriff’s officials estimated that 25 to 30 gallons spilled.

The acid on the ground was neutralized with baking soda, turning it into salt, said Lena Kent, spokeswoman for Burlington Northern.

She said it appears that the acid got under the liner of the car, causing the leak. The car was inspected on departure and nothing seemed amiss, she said.

The railroad planned to set up a claims process for affected residents to be re-imbursed for lodging, food and fuel. A claims center will be open from noon to 6 p.m. today at Monument City Hall and from 8 a.m. to 6 p.m. in the following days, until further notice.

“Everyone really jumped in and responded well and we were able to get the situation under control,” Kent said.