Prominent Twin Cities attorney Donald M. Lewis has been retained by the city of St. Paul to lead an independent investigation into a May 22 landslide at Lilydale Regional Park that killed two schoolchildren on a field trip and injured two others.

Lewis, co-founder of the Minneapolis law firm Nilan Johnson Lewis and dean of the Hamline University School of Law, will oversee an independent and wide-ranging review of internal city processes regarding the landslide, said Mayor Chris Coleman, who announced the hiring on Friday. Those specific processes could include a review of several city departments.

The investigation is separate from the one being led by Northern Technologies Inc., a civil engineering firm based in Fargo with expertise in such accidents. It was hired by St. Paul to determine what caused the side of a waterlogged hillside to collapse. Results from that inquiry are expected in a few weeks.

Fourth-graders Mohamed Fofana, 10, and Haysem Sani, 9, from Peter Hobart Elementary School in St. Louis Park, died after the cliff collapsed, and two other children were injured. The students had been hunting for fossils at the popular site.

Before becoming dean at the Hamline Law School five years ago, Lewis served for six years as an assistant U.S. attorney in Minneapolis and was a trial attorney in the Civil Rights Division of the U.S. Justice Department in Washington.

Lewis will start his work on Monday, the mayor said. "I have full faith that he will conduct this independent investigation in a robust and thorough manner," Coleman said. "The families of [Mohamed] and Haysem deserve nothing less."

Jim Anderson • 651-925-5039

Twitter: @StribJAnderson