Six-day derny pacer and former cyclist Cees Stam remains in critical condition after a crash in the Six-Days of Amsterdam last night. Stam fell while pacing his grandson Yoeri Havik in the derny race in the second night and took down others in the accident.

The 68-year-old Dutchman spent the night at the University Hospital in Amsterdam. “Stam has displayed some positive signs overnight, but his condition overall remains critical,” read a race statement today. “The organisation remains in close contact with the family.”

The organiser cut racing short last night after the accident. It wrote, “A number of other pacers and riders were involved in the incident. All are well, although some have minor injuries.”

Stam fell into Nick Stöpler as he came off his bike on the 200-metre track. Carlton Kirby, who is commentating on the event, wrote in Twitter, “He was stabilised track side before being taken to hospital.”

Some spectators reported that Stam fainted prior to crashing.

Stam raced mostly as track racer, setting the derny hour record in 1974, but never won a six-day race. His son Danny Stam also raced, winning 16 six-day races.

Paris-Roubaix winner Niki Terpstra (Omega Pharma-Quick Step) is partnering Havik at the Six-Days of Amsterdam and was sitting in the infield when the crash occurred. They led the race heading into day two.

The six-day, which runs until Saturday, will resume with day three this evening. Belgium’s Kenny De Ketele and Gijs Van Hoecke won the race in 2013.