Helloween are a German power metal band founded in 1984 in Hamburg, Northern Germany by members of bands Iron Fist and Gentry. Its first line-up consisted of singer and rhythm guitarist Kai Hansen, bass guitarist Markus Grosskopf, lead guitarist Michael Weikath, and drummer Ingo Schwichtenberg. After the release of a self-titled EP and their debut album Walls of Jericho in 1985, it expanded into a quintet with the addition of singer Michael Kiske, Hansen choosing to focus on guitar instead. Under this line-up, they released the Keeper of the Seven Keys albums (1987 and 1988), which established Helloween as a notable heavy metal band and led to the creation of the power metal subgenre.

Guitarist Kai Hansen unexpectedly left the band in 1989 soon after the European leg of the Keeper of the Seven Keys: Part II tour, due to ill-health, conflicts within the band, troubles with Noise International, and a growing dissatisfaction with life on tour. Weikath chose his friend Roland Grapow to replace him, including for the rest of the tour. Grapow, who was a car mechanic at the time, stated in 2017 that, if Weikath had not happened to ask him to join the band, he would have kept his job and given up on his dream of becoming a professional musician.  In 1989, the band released a live album called Live in the U.K. (Keepers Live in Japan and I Want Out Live in the United States), featuring material from its 1988 European tour. The remaining members continued on but ran into label problems with Noise, and after litigation kept them from touring and releasing new material, they were eventually released from their contract. A new album would not appear until 1991 when, after several rumors about the band breaking up, they released Pink Bubbles Go Ape for their new record company, EMI. The album was less heavy and, with song titles such as "Heavy Metal Hamsters", "I'm Doing Fine, Crazy Man", and "Shit and Lobster", showed a shift toward - and an emphasis on - humor rather than the epic moods on previous releases. As a result, Pink Bubbles Go Ape failed both commercially and critically, and tensions started to build amongst the band members.  The pop-influenced follow-up Chameleon was released in 1993. Instead of taking a heavier approach, the band ventured into new territory, eschewing its signature double-guitar harmonies for synthesizers, horns, acoustic guitars, a children's chorus, country music, and swing. As with the previous album, Chameleon failed commercially and critically. Tensions within Helloween worsened, and the band split into three factions, with Michael Kiske and Ingo Schwichtenberg on one side, Michael Weikath and Roland Grapow on the other, and Markus Grosskopf in the middle, trying to keep peace between the four men.  Shortly after, the band began to disintegrate. During the Chameleon tour, the band would often play to half-filled venues. Drummer Ingo Schwichtenberg fell ill due to mental and drug-related issues, and was eventually fired, replaced by session drummer Ritchie Abdel-Nabi. Meanwhile, the conflicts within the rest of the band worsened, with Michael Weikath refusing to work any longer with Michael Kiske. The decision was made to fire Kiske. Since his firing, Kiske has not spoken positively about Helloween. In May 2008, Kiske released Past in Different Ways; an album featuring most of his old Helloween songs, albeit rearranged and re-recorded acoustically. Commenting on Kiske's dismissal, Grosskopf later said:  In addition to the firing of Kiske, Abdel-Nabi, whose inability to replicate Schwichtenberg's machine-gun style of drumming hindered Helloween's ability to play live fan-favorites like "Eagle Fly Free" and "How Many Tears", was let go by the band. 1993 would come to a close for Helloween with no singer, no drummer, and no record contract (EMI released the band from its agreement for the low sales numbers for Pink Bubbles Go Ape and Chameleon).

Answer the following question by taking a quote from the article: What led to Hansen and Kiske's departures?
Guitarist Kai Hansen unexpectedly left the band in 1989 soon after the European leg of the Keeper of the Seven Keys: Part II tour,