Workers returned to 345 Park Ave., on Monday​ under the watchful eyes of NYPD officers and a surplus of security after the NYC mass shooting.

Rudin employee Julia Hyman was killed on the 33rd floor where Tamura shot and killed himself. A person close to Tamura's family says the gunman had for years sought medical help for frequent debilitating headaches. He even received injections in the back of his head.