Eleven missionaries working with the Christian missionary organization, YWAM were killed in a horrible vehicle crash in Arusha, Tanzania, the Christian Post reports.

Eight others injured in the crash, involving a large truck that slammed into a YWAM bus after the truck’s brakes failed, remain in critical condition. Several other vehicles were also damaged in the collision.

The group was on their way home having just participated in a University of the Nations Executive Masters class.

“Not only have husbands and wives, friends and co-workers been lost, but also YWAM ministry leaders,” said Darlene Cunningham, who with her late husband, Loren Cunningham, led YWAM (Youth With a Mission).

“The individuals involved in running the Executive Masters were key YWAM leaders in the region — some leading flourishing YWAM bases; others giving leadership in the field of education and other spheres; others ministering in restricted-access locations where no one else would dare to go — and seeing the hand of God upon their ministries in amazing ways,” Darlene added.

YWAM was started in 1960 by Loren Cunningham to train young people for Christian leadership and has over 600 training schools around the world. It was also one of the first organizations to introduce a short-term mission program and annually sends out about 25,000 people to serve in countries around the world.