Denver • The mother of a Denver resident says that he was among the hundreds killed in the attacks in Sri Lanka.

Dieter Kowalski’s mother, Inge Kowalski, told The Associated Press Monday by phone from Madison, Wisconsin, that she is working with the U.S. embassy to bring her son’s body back to the United States.

Kowalski was a senior leader of the operational technical services team for Pearson, an international educational company.

Pearson CEO John Fallon said in a statement that the 40-year-old Kowalski had just arrived at his Colombo hotel when he was killed in an explosion.

Fallon said Kowalski was big-hearted and known for helping to figure out the most challenging engineering problems.

At least 290 people died and 500 were injured in nine bomb blasts. Sri Lankan officials say the main attacks were carried out by seven suicide bombers from a local militant Muslim group.