The incident occurred shortly before 1 p.m. at a construction site on the 4400 block of Moravian Court, Philadelphia police said.
Medic 9 and Medic 41 transported two of the men to Peen Presbyterian Medical Center, both of whom were placed in critical condition, One of the men was pronounced dead at 12:59 p.m., police said.
Medic 41 also transported a third man to Lankenau Hospital, where "he remains in extremely critical condition," Officer Tanya Little, a police spokeswoman, said in a statement.
The scene was secured and is under investigation, she said.
A video of the scene was posted by Citizen here.
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