Investigators on Friday forged ahead with search and salvage operations after the collision of a passenger plane and a U.S. Army helicopter that killed 67 people, as families and communities across the U.S. and in other countries mourned the victims in the deadliest aviation disaster in over two decades.

Among the victims were people with ties to Oklahoma State University, Tinker Air Force Base and Oklahoma’s agriculture community.

Shortly before 9 p.m. on Wednesday night, American Airlines flight 5432 plunged into the Potomac River when it collided with an Army UH-60 Black Hawk conducting a “routine” training exercise. All 64 aboard the plane bound from Wichita, Kansas to D.C. are presumed dead, as are the three soldiers who occupied the helicopter.

Wednesday’s collision is the worst crash involving a U.S. airline since February 2009.

Here’s what we know about some of the victims who had ties to Oklahoma:

Lindsey Fields: Dedicated to ‘changing students’ lives every day’

Forgan native Lindsey Fields was headed to Washington, D.C. to advocate for excellence in life science education.

She was president-elect of the National Association of Biology Teachers, a role she was eager to step into because it was the same position her father Todd Carter held in 2008.

For the past decade, Fields taught biology at Butler Community College in the Wichita area. She was beloved at the school, who praised her energy and dedication to her craft.

“Lindsey was a colleague, friend, and educator who dedicated her wisdom and talents to changing students’ lives every day. We owe her much gratitude for sharing her light with us and we will forever feel this loss. We send much love and support to her family and friends during this most difficult time,” the school said in an announcement Friday morning.

Fields, a graduate of Forgan High School in the Oklahoma Panhandle, earned a master’s degree in zoology from Oklahoma State University. After that, she took an internship with the Oklahoma City Zoo working with big cats. According to an online biography, Fields’ graduate research led her to Kansas where she examined water quality of reservoirs on the central plains.

Oklahoma State Professor Andy Dzialowski was her coursework adviser at the university. He said that Fields took on the rare job of being an undergraduate teaching assistant, which is a role usually reserved for post-graduate students.

“If you asked people in her department who would have been one of the most successful teachers, it would be Lindsey. She was a really good teaching assistant,” he said. “She was a really nice person. A great big smile.”

Dzialowski feels humbled to see that Fields became so successful in her field.

“Students appreciate someone who’s dedicated to teaching them. Even if you don’t become a biologist, it’s important that you understand science,” he said. “Being a biology professor and teaching general biology courses really has a significance in our society.”

Andrew Eaves, a Black Hawk instructor pilot, served at Tinker AFB

One of the pilots on board the U.S. Army Black Hawk was Chief Warrant Officer 2 Andrew Eaves, who was serving as an instructor pilot.

Before joining the Army’s warrant officer program to fly helicopters, Eaves was a sailor stationed at Tinker Air Force Base.

Eaves was a native of Brooksville, Mississippi. His wife, Carrie Eaves, shared the news in a post on Facebook.

“We ask that you pray for our family and friends and for all the other families that are suffering today,” she wrote.

The Army said the Black Hawk, from the 12th Aviation Battalion, Davison Army Airfield in Fort Belvoir, Virginia, was on a training mission when it collided with the American Airlines jet.

Bob and Lori Schrock: Compassionate, eager to help others

Robert “Bob” and Lori Schrock were known in their community as compassionate people.

Bob, 58, and Lori, 56, lived in Kiowa, Kansas, which sits on the border with Oklahoma near Alva. Bob worked there as a farmer, their daughter Ellie told The Washington Post. The Oklahoman, which is part of the USA Today Network, reached out to Ellie, who wasn’t immediately available to speak about her parents.

The couple was flying out of Wichita that week and planned to ride the train to visit their daughter in Philadelphia. It was a typical trip the two took.  

Michael Simpson, a longtime family friend, shared that the couple were quick to lend a hand. Bob was one of the few men who encouraged him, Simpson said on social media, and he often sought Bob out for advice throughout his life.

“[They were] always silent in the background and never looking for any appreciation. They had a strong, vocal relationship with the Lord and I look forward to seeing my friends again. One of the last times we talked was about how amazing heaven will be and how excited we were about the hope we have, but until then we have a job to do for the Kingdom,” Simpson wrote on Facebook.

Simpson said while he misses his friends, he is praying for Ellie’s future.  

“Biggest heartbreak that we’ve been both praying about is their daughter because I can’t imagine how lonely that is going to feel. For me, for Mark, we’re going to hurt; it’s going to be painful, but we know we’re going to see our friends again,” he told KSN News.

Ellie’s close friend Grace Cantrell shared with reporters that she mourns the moments that the three will no longer be able to share.

“All the things that her parents won’t be there for, her wedding, her first boyfriend, her first kid, she’s planning on going to med school. If she becomes a doctor, they won’t get to see her achieve that,” Cantrell told KSN News.

Lici Beveridge of the Hattiesburg American contributed to this story.