The NFL, which is headquartered there, told employees to work remotely through at least Friday.
Blackstone employees have the choice to return to the office Monday or to work remotely.
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Blackstone real estate executive Wesley LePatner was among those who were killed in the attack.
Meanwhile, funeral services were announced for security guard Aland Etienne, 46, also killed in the attack. He will be laid to rest on Saturday August 9 in Canarsie, Brooklyn.
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As for the shooter, a person close to Shane Tamura's family says the gunman had for years sought medical help for frequent debilitating headaches. He even receive injections in the back of his head.
In a suicide note, Tamura claimed he suffered from CTE from playing football, and requested that his brain be studied.