Authorities say Hendron had burst into the main offices of ABB power company and opened fire, leaving several people dead or wounded.
Authorities late Thursday morning said that a total of three people were dead and four left wounded in the attack. Police Capt. Sam Dotson confirmed the number but said he did not have names or details about the victims.
Officers surrounded the building as they searched for the gunman who was initially believed to still be in the building. About four hours after the rampage, police sources reported that the gunman had been located in the building and was shot and wounded. There are also reports by some St. Louis media that he is among the dead.
The shooting occurred around 6:30 a.m. Fire Department spokesman Bob Keuss identified the suspected shooter as Timothy Hendron of Webster Groves. Those who know Hendron say he is a long time employee of the company, according to local press reports. Swiss-based ABB Group makes power transmission and industrial automation equipment and manufactures transformers at the St. Louis site. Many of the 40 or 50 employees inside the plant at the time of the shooting hid on the rooftop, in boiler rooms and in closets.
The class-action federal lawsuit against ABB was filed by Hendron and several other employees in July, 2007. The suit charged that ABB's pension review committee mis handled employee finances and incurred unreasonable losses.
Trial began on Monday in Kansas City federal court with Judge Nanette K. Laughrey presiding. Opening statements had taken place and witness testimony began. The case was to resume Thursday morning, a little more than two hours after the shots were fired and blood spilled at ABB in St. Louis.