Dallas police say a 44-year-old man fell 150 feet to his death as police tried to coax him down from a construction crane after a more than 14-hour standoff.

Police say Lee Dell Thomas Jr., 44, died early Tuesday after slipping from the cab of the crane on the Southern Methodist University campus.

Thomas scrambled up the crane and into the cab around midday Monday. The cab was fully exposed to the blazing sun and 90-degree temperatures. Thomas warned officers that he was armed and would shoot anyone who approached him.

Two SWAT team members who climbed the crane around 1 a.m. Tuesday discovered Thomas had barricaded himself in the cab and covered the surrounding area with grease to prevent them from reaching him, the Dallas Police Department said in a statement. Thomas then sprayed a grease "similar to WD-40" toward the officers, police said.

Thomas pulled himself out of the cab and briefly hung from the crane -- clinging on with just his hands -- before dropping to his death at 1:47 a.m. Tuesday.

Police did not say if any weapon had been recovered. Authorities are investigating if Thomas was involved in an earlier robbery, the police statement said.

The campus was closed for Memorial Day, but reopened Tuesday.

Click for more from myFOXdfw.com.