About 200 employees of insurance giant, Aon, still remain unaccounted for as a result of the World trade Center disaster. Aon occupied floors 92 and 98-105 of Two World Trade Center. The firm says that approximately 1,350 of its employees were potentially at risk during Tuesday’s tragedy.

That includes approximately 1,100 employees who were based in the Two World Trade Center offices and approximately 250 employees who were either traveling to New York City at that time or were located in Aon’s other lower Manhattan offices.

“While we are grateful that approximately 1,150 are safe, we are deeply saddened that we still cannot confirm the safety of approximately 200 of our Aon colleagues. We continue to work to locate the missing, and we pray for their safe return,” said Aon’s chief Patrick Ryan. “We are deeply moved by the way the Aon community around the world has rallied to help us respond to colleagues in need.”

Ryan says that it has been working around the clock to provide support for employees and families who were directly affected, at its 24-hour call center, on the ground in the New York area, and in many other locations around the world. Aon has established Crisis Support Centers, at locations throughout the New York metropolitan area, to provide group and individual counseling to employees and families, and to provide employee benefits guidance. It is also opening additional facilities in New York, New Jersey and Connecticut.

The firm is offering travel assistance and to reimburse travel expenses for immediate family members of employees who are critically injured, missing, or deceased. It is providing enhancements to its standard medical coverage and short-term disability policies. It is also making financial counseling available.

Aon has established an assistance fund to provide financial help to employees and family members affected by Tuesday’s events. It will match donations, and plans to make its own substantial contribution.