A utility worker was electrocuted Tuesday and another severely burned as crews tried to restore power to more than 150,000 homes and businesses that have been without air conditioning for nearly a week.

Officials with Ameren Corp. said a 56-year-old utility worker died when he stepped on branches covering a live wire in suburban Ladue.

The utility identified him as Robert Tackett, of St. Charles, and said he had worked for Ameren for 13 years.

"We are heartbroken that we have lost a valued employee and friend, who was both highly dedicated and experienced," said Thomas Voss, executive vice president and chief operating officer of Ameren.

The other worker, a contract worker employed by Kansas City-based Par Electric, had been brought in to help the recovery effort. He was hospitalized with electrical burns after he was shocked by 7,000 volts of electricity while climbing a pole in the town of Spanish Lake, Voss said. He said the worker was expected to recover.

More than half a million homes lost power when thunderstorms swept through the area Wednesday evening, and more went down when another storm hit on Friday. Ameren officials said most of the remaining customers still without power should have their electricity restored Wednesday.

High temperatures in the low 90s were forecast for Tuesday.

The death Tuesday was the fifth in the region attributed to the storms or heat and the first of an electrical worker.

About 4,000 Ameren employees and independent contractors are working 16-hour shifts to restore power, according to Ameren.