A recent study conducted by the Philadelphia Inquirer showed that the artificial turf at Veterans Stadium, the longtime former home of Major League Baseball’s Philadelphia Phillies and the National Football League’s Philadelphia Eagles, had cancerous chemicals, which may have been the cause of several former Phillies players’ deaths.

The Inquirer launched its investigation into the Vet’s turf after relief pitcher David West became the sixth former Phillies player to have died from glioblastoma, a rare, aggressive form of brain cancer, following Tug McGraw, John Vukovich, Ken Brett, Dan Quisenberry and Johnny Oates, all of whom died before the age of 60. The study found that the turf, which was produced by Monsanto and used at the stadium from 1977 to 2001, had dangerous “forever chemicals.”

The chemicals are connected to several forms of cancer, including brain cancer, which claimed the lives of six of the 532 former Phillies players who played at the Vet from 1971 to 2003, more than triple the average rate of adult men.

Veterans Stadium was demolished in 2004 with the Phillies moving to Citizens Bank Park and the Eagles moving to Lincoln Financial Field that same year.