A new proof of the Solomon-Tits theorem
Chao Ku
Department of Mathematics, Caltech, Pasadena, California 91125 

Proc. Amer. Math. Soc. 126 (1998), 1941-1944.

Abstract. We give a new proof of the Solomon-Tits Theorem which asserts that the Tits building of a finite group of Lie type has the homotopy type of a
bouquet of spheres.